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Sample records for mode iii effects

  1. Effects of friction and high torque on fatigue crack propagation in Mode III

    NASA Astrophysics Data System (ADS)

    Nayeb-Hashemi, H.; McClintock, F. A.; Ritchie, R. O.

    1982-12-01

    Turbo-generator and automotive shafts are often subjected to complex histories of high torques. To provide a basis for fatigue life estimation in such components, a study of fatigue crack propagation in Mode III (anti-plane shear) for a mill-annealed AISI 4140 steel (RB88, 590 MN/m2 tensile strength) has been undertaken, using torsionally-loaded, circumferentially-notched cylindrical specimens. As demonstrated previously for higher strength AISI 4340 steel, Mode III cyclic crack growth rates (dc/dN) IIIcan be related to the alternating stress intensity factor ΔKIII for conditions of small-scale yielding. However, to describe crack propagation behavior over an extended range of crack growth rates (˜10-6 to 10-2 mm per cycle), where crack growth proceeds under elastic-plastic and full plastic conditions, no correlation between (dc/dN) III and ΔKIII is possible. Accordingly, a new parameter for torsional crack growth, termed the plastic strain intensity Γ III, is introduced and is shown to provide a unique description of Mode III crack growth behavior for a wide range of testing conditions, provided a mean load reduces friction, abrasion, and interlocking between mating fracture surfaces. The latter effect is found to be dependent upon the mode of applied loading (i.e., the presence of superimposed axial loads) and the crack length and torque level. Mechanistically, high-torque surfaces were transverse, macroscopically flat, and smeared. Lower torques showed additional axial cracks (longitudinal shear cracking) perpendicular to the main transverse surface. A micro-mechanical model for the main radi l Mode III growth, based on the premise that crack advance results from Mode II coalescence of microcracks initiated at inclusions ahead of the main crack front, is extended to high nominal stress levels, and predicts that Mode III fatigue crack propagation rates should be proportional to the range of plastic strain intensity (ΔΓIII if local Mode II growth rates are

  2. Effects of hydrogen on the mixed mode I/III toughness of a high-purity rotor steel

    SciTech Connect

    Kumar, A.M.; Hirth, J.P. ); Moody, N.R.; Gordon, J.A. )

    1993-06-01

    Recently, the authors reported the effects of hydrogen on the mixed mode 1/111 toughness of a high-purity Ni-Cr-Mo-V rotor steel. The steel was tested both in the uncharged and hydrogen-charged conditions. It was shown that the presence of hydrogen degraded the overall J toughness incrementally by approximately 30 pct, with the degree of degradation increasing with the mode III component. Also, in the uncharged condition, the J toughness decreased to a minimum as the mode I/III ratio decreased and increased again for pure mode III loading. However, the authors could not determine if a similar variation of toughness was displayed by the hydrogen-charged steel, because the pure mode III tests could not be completed at that time. The pure mode III tests are now complete, and these new results are presented in this communication. The chemical composition of the steel used in these studies was 0.25C-3.7Ni-1.7Cr-0.4Mo-0.12V-0.05Mn- 0.02Si-0.003(P,Sn,As)-O.002Sb-0.0015 S (wt pct).

  3. Complexation of uranium(VI) and samarium(III) with oxydiacetic acid: temperature effect and coordination modes.

    PubMed

    Rao, Linfeng; Garnov, Alexander Yu; Jiang, Jun; Di Bernardo, Plinio; Zanonato, PierLuigi; Bismondo, Arturo

    2003-06-01

    The complexation of uranium(VI) and samarium(III) with oxydiacetate (ODA) in 1.05 mol kg(-1) NaClO(4) is studied at variable temperatures (25-70 degrees C). Three U(VI)/ODA complexes (UO(2)L, UO(2)L(2)(2-), and UO(2)HL(2)(-)) and three Sm(III)/ODA complexes (SmL(j)((3-2)(j)+) with j = 1, 2, 3) are identified in this temperature range. The formation constants and the molar enthalpies of complexation are determined by potentiometry and calorimetry. The complexation of uranium(VI) and samarium(III) with oxydiacetate becomes more endothermic at higher temperatures. However, the complexes become stronger due to increasingly more positive entropy of complexation at higher temperatures that exceeds the increase in the enthalpy of complexation. The values of the heat capacity of complexation (Delta C(p) degrees in J K(-1) mol(-1)) are 95 +/- 6, 297 +/- 14, and 162 +/- 19 for UO(2)L, UO(2)L(2)(2-), and UO(2)HL(2)(-), and 142 +/- 6, 198 +/- 14, and 157 +/- 19 for SmL(+), SmL(2)(-), and SmL(3)(3-), respectively. The thermodynamic parameters, in conjunction with the structural information from spectroscopy, help to identify the coordination modes in the uranium oxydiacetate complexes. The effect of temperature on the thermodynamics of the complexation is discussed in terms of the electrostatic model and the change in the solvent structure. PMID:12767209

  4. Modeling Quantum and Coulomb Effects in Nanoscale Enhancement-Mode Tri-Gate III-V MOSFETs

    NASA Astrophysics Data System (ADS)

    Al-Sibiani, Sameer; Khair, Khadija; Ahmed, Shaikh

    2014-03-01

    Because of limited benefits of strain engineering in extremely scaled silicon devices and lack of demonstration of a performance gain at the product level with nanowires, nanotubes, graphene, and other exotic channel materials, there is a strong motivation to continue device scaling using high-transport III-V (such as InGaAs and InAsSb) channel materials beyond the year 2020. However, there are several challenges with III-V MOSFETs prohibiting their use in high-performance and low-power logic applications. In this work, we investigate the performance of the tri-gate III-V FETs as compared to the planar counterpart, and show how quantum size quantization and random dopant fluctuations (RDF) affect the tri-gate FET characteristics and how to curb these issues. A 3-D fully atomistic quantum-corrected Monte Carlo device simulator has been used in this work. Space-quantization effects have been accounted for via a parameter-free effective potential scheme (and benchmarked against the NEGF approach in the ballistic limit). To treat full Coulomb (electron-ion and electron-electron) interactions, the simulator implements a real-space corrected Coulomb electron dynamics (ED) scheme. Also, the essential bandstructure parameters (bandgap, effective masses, and the density-of-states) have been computed using a 20-band nearest-neighbour sp3d5s* tight-binding scheme.

  5. Adiabatic Survey of Subdwarf B Star Oscillations. III. Effects of Extreme Horizontal Branch Stellar Evolution on Pulsation Modes

    NASA Astrophysics Data System (ADS)

    Charpinet, S.; Fontaine, G.; Brassard, P.; Dorman, Ben

    2002-06-01

    We present the final results of a large, systematic survey of the adiabatic oscillation properties of models of subdwarf B (sdB) stars. This survey is aimed at providing the minimal theoretical background with which to understand the asteroseismological characteristics of the recently discovered class of pulsating sdB stars (the EC 14026 objects). In this paper, the last of a series of three, we consider the effects of stellar evolution on the pulsation eigenmodes of sdB star models. We specifically analyze the adiabatic properties of 149 equilibrium models culled from seven distinct extreme horizontal branch evolutionary sequences. Those have been chosen in order to span fully the region of parameter space where real sdB stars are found. We primarily focus on the evolution of the pulsation periods (P) and the rates of period change (dP/dt), which are both a priori observable quantities. Both the acoustic and gravity branches of stellar oscillations are considered. In light of the results derived in the first two papers of this series, we discuss how the values of P and dP/dt relate to the various structural adjustments that sdB stars undergo during evolution. We find that the acoustic modes react primarily to the secular variations of the surface gravity. In contrast, we identify three main factors that regulate the period evolution of gravity modes: these are the variations brought about by evolution in both the surface gravity and the effective temperature, as well as the onset and growth of a chemical discontinuity between the C-O-enriched nucleus and the helium-rich mantle. We also find, as expected from our previous results, that the period evolution of the pulsation modes in sdB stars is further complicated by trapping effects (microtrapping in the case of p-modes) and by avoided crossings between modes. The latter occur preferentially in certain regions of parameter space. We provide our final results in the form of extensive tabular data in the appendices

  6. Fracture toughness of quaternary Al-Li-Cu-Mg alloy under mode I, mode II, and mode III loading conditions

    SciTech Connect

    Prasad, N.E.; Kamat, S.V.; Malakondaiah, G. ); Kutumbarao, V.V. . Dept. of Metallurgical Engineering)

    1994-11-01

    The fracture toughness under mode I, mode II, and mode III loading conditions was evaluated for a quaternary 8090 Al-Li-Cu-Mg alloy in underaged and peak-aged conditions. The effect of aging was found to be significantly different for different loading conditions. The alloy in the underaged (T3) condition exhibited minimum fracture toughness under mode II loading, whereas mode I fracture toughness was the lowest in the case of the peak-aged (T8E51) condition. Significant anisotropy in the fracture resistance is observed only in case of the peak-aged alloy under mode I loading, whereas in all other cases, the fracture resistance is found to be isotropic. The fracture mode was transgranular shear in all three modes of loading in the underaged condition as well as under mode II and mode III loading in the peak-aged condition. The alloy exhibited ductile intergranular fracture under mode I loading in the peak-aged condition. The results obtained are explained on the basis of these dominant fracture mechanisms prevalent under different loading conditions.

  7. Comparison of fatigue crack propagation in Modes I and III

    SciTech Connect

    Ritchie, R.O.

    1985-06-01

    The propagation behavior of fatigue cracks in Mode III (anti-plane shear), measured under cyclic torsion, is described and compared with more commonly encountered behavior under Mode I (tensile opening) loads. It is shown that a unique, global characterization of Mode III growth rates, akin to the Paris ''law'' in Mode I, is only possible if characterizating parameters appropriate to large-scale yielding are employed and allowance is made for crack tip shielding from sliding crack surface interference (i.e., friction and abrasion) between mating fracture surfaces. Based on the crack tip stress and deformation fields for Mode III stationary cracks, the cyclic crack tip displacement, (..delta..CTD/sub III/, and plastic strain intensity range ..delta..GAMMA/sub III/, have been proposed and are found to provide an adequate description of behavior in a range of steels, provided crack surface interference is minimized. The magnitude of this interference, which is somewhat analogous to crack closure in Mode I, is further examined in the light of the complex fractography of torsional fatigue failures and the question of a ''fatigue threshold'' for Mode III crack growth. Finally, micro-mechanical models for cyclic crack extension in anti-plane shear are briefly described, and the contrasting behavior between Mode III and Mode I cracks subjected to simple variable amplitude spectra is examined in terms of the differing role of crack tip blunting and closure in influencing shear, as opposed to tensile opening, modes of crack growth.

  8. Mode III fatigue crack propagation in low alloy steel

    NASA Astrophysics Data System (ADS)

    Ritchie, R. O.; McClintock, F. A.; Nayeb-Hashemi, H.; Ritter, M. A.

    1982-01-01

    To provide a basis for estimating fatigue life in large rotating generator shafts subjected to transient oscillations, a study is made of fatigue crack propagation in Mode III (anti-plane shear) in torsionally-loaded spheroidized AISI4340 steel, and results compared to analogous behavior in Mode I. Torsional S/N curves, determined on smooth bars containing surface defects, showed results surprisingly close to expected unnotched Mode I data, with lifetime increasing from 104 cycles at nominal yield to 106 cycles at half yield. Fatigue crack growth rates in Mode III, measured on circumferentially-notched samples, were found to be slower than in Mode I, although still power-law related to the alternating stress intensity (△K III) for small-scale yielding. Mode III growth rates were only a small fraction (0.002 to 0.0005) of cyclic crack tip displacements (△CTD III) per cycle, in contrast to Mode I where the fraction was much larger (0.1 to 0.01). A micromechanical model for Mode III growth is proposed, where crack advance is considered to take place by a Mode II coalescence of cracks, initiated at inclusions ahead of the main crack front. This mechanism is consistent with the crack increment being a small fraction of △CTDIII per cycle.

  9. Mode III fatigue crack propagation in low alloy steel

    SciTech Connect

    Ritchie, R.O.; McClintock, F.A.; Nayeb-Hashemi, H.; Ritter, M.A.

    1982-01-01

    To provide a basis for estimating fatigue life in large rotating generator shafts subjected to transient oscillations, a study is made of fatigue crack propagation in Mode III (anti-plane shear) in torsionally-loaded spheroidized AISI 4340 steel. Results are compared to analogous behavior in Mode I. The approach investigated the feasibility of using continuum fracture mechanics and preliminary mechanistic modeling to serve as a basis for defect-tolerant life estimation procedures. 38 refs.

  10. Complexation of Curium(III) with DTPA at 10–70 °C: Comparison with Eu(III)–DTPA in Thermodynamics, Luminescence, and Coordination Modes

    SciTech Connect

    Tian, Guoxin; Zhang, Zhiyong; Martin, Leigh R.; Rao, Linfeng

    2015-02-16

    Separation of trivalent actinides (An(III)) from trivalent lanthanides (Ln(III)) is a challenging task because of their nearly identical chemical properties. Diethylenetriaminepentaacetate (DTPA), a key reagent used in the TALSPEAK process that effectively separates An(III) from Ln(III), is believed to play a critical role in the An(III)/Ln(III) separation. However, the underlying principles for the separation based on the difference in the complexation of DTPA with An(III) and Ln(III) remain unclear. In this work, the complexation of DTPA with Cm(III) at 10-70 ºC was investigated by spectrophotometry, luminescence spectroscopy, and microcalorimetry, in conjunction with computational methods. The binding strength, the enthalpy of complexation, the coordination modes, and the luminescence properties are compared between the Cm(III)-DTPA and Eu(III)-DTPA systems. The experimental and computational data have demonstrated that the difference between Cm(III) and Eu(III) in the binding strength with DTPA can be attributed to the stronger covalence bonding between Cm(III) and the nitrogen donors of DTPA.

  11. Complexation of curium(III) with DTPA at 10-70 °C: comparison with Eu(III)-DTPA in thermodynamics, luminescence, and coordination modes.

    PubMed

    Tian, Guoxin; Zhang, Zhiyong; Martin, Leigh R; Rao, Linfeng

    2015-02-16

    Separation of trivalent actinides (An(III)) from trivalent lanthanides (Ln(III)) is a challenging task because of the nearly identical chemical properties of these groups. Diethylenetriaminepentaacetate (DTPA), a key reagent used in the TALSPEAK process that effectively separates An(III) from Ln(III), is believed to play a critical role in the An(III)/Ln(III) separation. However, the underlying principles for the separation based on the difference in the complexation of DTPA with An(III) and Ln(III) remain unclear. In this work, the complexation of DTPA with Cm(III) at 10-70 °C was investigated by spectrophotometry, luminescence spectroscopy, and microcalorimetry, in conjunction with computational methods. The binding strength, the enthalpy of complexation, the coordination modes, and the luminescence properties are compared between the Cm(III)-DTPA and Eu(III)-DTPA systems. The experimental and computational data demonstrated that the difference between Cm(III) and Eu(III) in the binding strength with DTPA can be attributed to the stronger covalence bonding between Cm(III) and the nitrogen donors of DTPA.

  12. Mixed-mode I/III fracture toughness of a ferritic/martensitic stainless steel

    SciTech Connect

    Li, Huaxin; Jones, R.H.; Gelles, D.S.; Hirth, J.P.

    1993-10-01

    The critical J-integrals of mode I (J{sub IC}), mixed-mode I/III (J{sub MC}), and mode III (J{sub IIIC}) were examined for a ferritic stainless steel (F-82H) at ambient temperature. A determination of J{sub MC} was made using modified compact-tension specimens. Different ratios of tension/shear stress were achieved by varying the principal axis of the crack plane between 0 and 55 degrees from the load line. Results showed that J{sub MC} and tearing modulus (T{sub M}) values varied with the crack angles and were lower than their mode I and mode III counterparts. Both the minimum J{sub MC} and T{sub M} values occurred at a crack angle between 40 and 50 degrees, where the load ratio of {sigma}{sub i}/{sigma}{sub iii} was 1.2 to 0.84. The J{sub min} was 240 Kj/M{sup 2}, and ratios of J{sub IC}/J{sub min} and J{sub IIIC}/J{sub min} were 2.1 and 1.9, respectively. The morphology of fracture surfaces was consistent with the change of J{sub MC} and T{sub M} values. While the upper shelf-fracture toughness of F-82H depends on loading mode, the J{sub min} remains very high. Other important considerations include the effect of mixed-mode loading on the DBT temperature, and effects of hydrogen and irradiation on J{sub min}.

  13. Is the Pharmacological Mode of Action of Chromium(III) as a Second Messenger?

    PubMed

    Vincent, John B

    2015-07-01

    Although recent studies have shown that chromium (as the trivalent ion) is not an essential trace element, it has been demonstrated to generate beneficial effects at pharmacologically relevant doses on insulin sensitivity and cholesterol levels of rodent models of insulin insensitivity, including models of type 2 diabetes. The mode of action of Cr(III) at a molecular level is still an area of active debate; however, the movement of Cr(III) in the body, particularly in response to changes in insulin concentration, suggests that Cr(III) could act as a second messenger, amplifying insulin signaling. The evidence for the pharmacological mechanism of Cr(III)'s ability to increase insulin sensitivity by acting as a second messenger is reviewed, and proposals for testing this hypothesis are described.

  14. III-nitride tunable cup-cavities supporting quasi whispering gallery modes from ultraviolet to infrared

    PubMed Central

    Shubina, T. V.; Pozina, G.; Jmerik, V. N.; Davydov, V. Yu.; Hemmingsson, C.; Andrianov, A. V.; Kazanov, D. R.; Ivanov, S. V.

    2015-01-01

    Rapidly developing nanophotonics needs microresonators for different spectral ranges, formed by chip-compatible technologies. In addition, the tunable ones are much in demand. Here, we present site-controlled III-nitride monocrystal cup-cavities grown by molecular beam epitaxy. The cup-cavities can operate from ultraviolet to near-infrared, supporting quasi whispering gallery modes up to room temperature. Besides, their energies are identical in large ’ripened’ crystals. In these cavities, the refractive index variation near an absorption edge causes the remarkable effect of mode switching, which is accompanied by the spatial redistribution of electric field intensity with concentration of light into a subwavelength volume. Our results shed light on the mode behavior in semiconductor cavities and open the way for single-growth-run manufacturing the devices comprising an active region and a cavity with tunable mode frequencies. PMID:26656267

  15. III-nitride tunable cup-cavities supporting quasi whispering gallery modes from ultraviolet to infrared

    NASA Astrophysics Data System (ADS)

    Shubina, T. V.; Pozina, G.; Jmerik, V. N.; Davydov, V. Yu.; Hemmingsson, C.; Andrianov, A. V.; Kazanov, D. R.; Ivanov, S. V.

    2015-12-01

    Rapidly developing nanophotonics needs microresonators for different spectral ranges, formed by chip-compatible technologies. In addition, the tunable ones are much in demand. Here, we present site-controlled III-nitride monocrystal cup-cavities grown by molecular beam epitaxy. The cup-cavities can operate from ultraviolet to near-infrared, supporting quasi whispering gallery modes up to room temperature. Besides, their energies are identical in large ’ripened’ crystals. In these cavities, the refractive index variation near an absorption edge causes the remarkable effect of mode switching, which is accompanied by the spatial redistribution of electric field intensity with concentration of light into a subwavelength volume. Our results shed light on the mode behavior in semiconductor cavities and open the way for single-growth-run manufacturing the devices comprising an active region and a cavity with tunable mode frequencies.

  16. Subcritical crack growth under mode I, II, and III loading for Coconino sandstone

    NASA Astrophysics Data System (ADS)

    Ko, Tae Young

    In systems subjected to long-term loading, subcritical crack growth is the principal mechanism causing the time-dependent deformation and failure of rocks. Subcritical crack growth is environmentally-assisted crack growth, which can allow cracks to grow over a long period of time at stresses far smaller than their failure strength and at tectonic strain rates. The characteristics of subcritical crack growth can be described by a relationship between the stress intensity factor and the crack velocity. This study presents the results of studies conducted to validate the constant stress-rate test for determining subcritical crack growth parameters in Coconino sandstone, compared with the conventional testing method, the double torsion test. The results of the constant stress-rate test are in good agreement with the results of double torsion test. More importantly, the stress-rate tests can determine the parameter A with a much smaller standard deviation than the double torsion test. Thus the constant stress-rate test seems to be both a valid and preferred test method for determining the subcritical crack growth parameters in rocks. We investigated statistical aspects of the constant stress-rate test. The effects of the number of tests conducted on the subcritical crack growth parameters were examined and minimum specimen numbers were determined. The mean and standard deviation of the subcritical crack growth parameters were obtained by randomly selecting subsets from the original strength data. In addition, the distribution form of the subcritical crack growth parameters and the relation between the parameter n and A were determined. We extended the constant stress-rate test technique to modes II and III subcritical crack growth in rocks. The experimental results of the modes I, II and III tests show that the values of the subcritical crack growth parameters are similar to each other. The subcritical crack growth parameter n value for Coconino sandstone has the range

  17. Fracture behavior of quaternary Al-Li-Cu-Mg alloy under mixed mode I/III loading

    SciTech Connect

    Eswara Prasad, N.; Kamat, S.V.

    1995-07-01

    The fracture toughness under mixed-mode I/III loading conditions was evaluated for a quaternary 8090 Al-Li-Cu-Mg alloy in underaged and peak-aged conditions. The mixed-mode fracture behavior was found to be significantly different for the two aging conditions. Super-imposed mode III component lowered the fracture resistance of the alloy in underaged conditions, whereas it had no significant effect in peak-aged condition. The results obtained have been discussed in the light of the prevalent fracture processes, namely, transgranular shear and ductile intergranular fracture mechanisms. Further, these results are analyzed in terms of different fracture criteria and they were found to deviate significantly from those predicted by the energy release rate criterion.

  18. Helicon modes in uniform plasmas. III. Angular momentum

    NASA Astrophysics Data System (ADS)

    Stenzel, R. L.; Urrutia, J. M.

    2015-09-01

    Helicons are electromagnetic waves with helical phase fronts propagating in the whistler mode in magnetized plasmas and solids. They have similar properties to electromagnetic waves with angular momentum in free space. Helicons are circularly polarized waves carrying spin angular momentum and orbital angular momentum due to their propagation around the ambient magnetic field B0. These properties have not been considered in the community of researchers working on helicon plasma sources, but are the topic of the present work. The present work focuses on the field topology of helicons in unbounded plasmas, not on helicon source physics. Helicons are excited in a large uniform laboratory plasma with a magnetic loop antenna whose dipole axis is aligned along or across B0. The wave fields are measured in orthogonal planes and extended to three dimensions (3D) by interpolation. Since density and B0 are uniform, small amplitude waves from loops at different locations can be superimposed to generate complex antenna patterns. With a circular array of phase shifted loops, whistler modes with angular and axial wave propagation, i.e., helicons, are generated. Without boundaries radial propagation also arises. The azimuthal mode number m can be positive or negative while the field polarization remains right-hand circular. The conservation of energy and momentum implies that these field quantities are transferred to matter which causes damping or reflection. Wave-particle interactions with fast electrons are possible by Doppler shifted resonances. The transverse Doppler shift is demonstrated. Wave-wave interactions are also shown by showing collisions between different helicons. Whistler turbulence does not always have to be created by nonlinear wave-interactions but can also be a linear superposition of waves from random sources. In helicon collisions, the linear and/or orbital angular momenta can be canceled, which results in a great variety of field topologies. The work will

  19. Helicon modes in uniform plasmas. III. Angular momentum

    SciTech Connect

    Stenzel, R. L.; Urrutia, J. M.

    2015-09-15

    Helicons are electromagnetic waves with helical phase fronts propagating in the whistler mode in magnetized plasmas and solids. They have similar properties to electromagnetic waves with angular momentum in free space. Helicons are circularly polarized waves carrying spin angular momentum and orbital angular momentum due to their propagation around the ambient magnetic field B{sub 0}. These properties have not been considered in the community of researchers working on helicon plasma sources, but are the topic of the present work. The present work focuses on the field topology of helicons in unbounded plasmas, not on helicon source physics. Helicons are excited in a large uniform laboratory plasma with a magnetic loop antenna whose dipole axis is aligned along or across B{sub 0}. The wave fields are measured in orthogonal planes and extended to three dimensions (3D) by interpolation. Since density and B{sub 0} are uniform, small amplitude waves from loops at different locations can be superimposed to generate complex antenna patterns. With a circular array of phase shifted loops, whistler modes with angular and axial wave propagation, i.e., helicons, are generated. Without boundaries radial propagation also arises. The azimuthal mode number m can be positive or negative while the field polarization remains right-hand circular. The conservation of energy and momentum implies that these field quantities are transferred to matter which causes damping or reflection. Wave-particle interactions with fast electrons are possible by Doppler shifted resonances. The transverse Doppler shift is demonstrated. Wave-wave interactions are also shown by showing collisions between different helicons. Whistler turbulence does not always have to be created by nonlinear wave-interactions but can also be a linear superposition of waves from random sources. In helicon collisions, the linear and/or orbital angular momenta can be canceled, which results in a great variety of field

  20. Equilibrium Phase Diagrams for Stranski-Krastanov Structure Mode of III V Ternary Quantum Dots

    NASA Astrophysics Data System (ADS)

    Nakajima, Kazuo

    1999-04-01

    The strain, surface and interfacial energies of III V ternary systems were calculated for three kinds of structure modes: the Frank-van der Merwe (FM) mode, the Stranski-Krastanov (SK) mode and the Volmer-Weber (VW) mode. The free energy for each mode was estimated as functions of the thickness and composition or lattice misfit. Through comparison of the free energy of each mode, it was found that the thickness-composition phase diagrams of III V ternary systems can be determined only by considering the balance of the free energy and three kinds of structure modes appear in the phase diagrams. The SK mode appears only when the lattice misfit is large and/or the lattice layer is thick. The VW mode appears when the lattice misfit is large and the lattice layer is thin and only in the InPSb/InP and GaPSb/GaP systems which have the largest lattice misfit of III V ternary systems. The stable region of the SK mode in the GaPSb/GaP and InPSb/InP phase diagrams is largest of all because the composition dependence of the strain energy of these systems is stronger than that of the other systems. The critical number of lattice layers below which two-dimensional (2D) layers precede the three-dimensional (3D) nucleation in the SK mode at x=1.0 depends on the lattice misfit. In the InPSb/InP system, the smallest number of 2D layers precede the 3D nucleation in the SK mode.

  1. Comparison of Mode II and III Monotonic and Fatigue Delamination Onset Behavior for Carbon/Toughened Epoxy Composites

    NASA Technical Reports Server (NTRS)

    Li, Jian; OBrien, T. Kevin; Lee, Shaw Ming

    1997-01-01

    Monotonic and fatigue tests were performed to compare the Mode II and III interlaminar fracture toughness and fatigue delamination onset for Tenax-HTA/R6376 carbon/toughened epoxy composites. The Mode II interlaminar fracture toughness and fatigue delamination onset were characterized using the end-notched flexure (ENF) test while the Mode III interlaminar fracture toughness and fatigue delamination onset were characterized by using the edge crack torsion (ECT) test. Monotonic tests show that the Mode III fracture toughness is higher than the Mode II fracture toughness. Both Mode II and III cyclic loading greatly increases the tendency for a delamination to grow relative to a single monotonically increasing load. Under fatigue loading, the Mode III specimen also has a longer life than the Mode II specimen.

  2. Out-of-plane deviation of a mode I+III crack encountering a tougher obstacle

    NASA Astrophysics Data System (ADS)

    Leblond, Jean-Baptiste; Ponson, Laurent

    2016-07-01

    One possible explanation of out-of-plane deviations of cracks loaded in mode I+III was suggested by Gao and Rice in 1986. These authors noted that small in-plane undulations of the crack front, arising from fluctuations of the fracture toughness, should generate a small local mode-II component, causing the crack to depart from planarity. Their analysis is completed here by explicitly calculating the evolution in time of the out-of-plane deviation of a mode-I+III crack encountering a tougher obstacle. The calculation is based on (i) first-order formulae for the stress intensity factors of a crack slightly perturbed within and out of its plane; and (ii) a "double" propagation criterion combining a Griffith condition on the local energy-release rate and a Goldstein-Salganik condition on the local stress intensity factor of mode II. It is predicted that the crack must evolve toward a stationary state, wherein the orthogonal distance from the average fracture plane to the perturbed crack front is constant outside the obstacle and varies linearly across it. We hope that this theoretical prediction will encourage comparison with experiments, and propose a fracture test involving propagation of a mode-I+III crack through a 3D-printed specimen containing some designed obstacle. xml:lang="fr"

  3. The effective degeneracy of protein normal modes.

    PubMed

    Na, Hyuntae; Song, Guang

    2016-01-01

    Normal modes are frequently computed and used to portray protein dynamics and interpret protein conformational changes. In this work, we investigate the nature of normal modes and find that the normal modes of proteins, especially those at the low frequency range (0-600 cm(-1)), are highly susceptible to degeneracy. Two or more modes are degenerate if they have the same frequency and consequently any orthogonal transformation of them also is a valid representation of the mode subspace. Thus, degenerate modes can no longer characterize unique directions of motions as regular modes do. Though the normal modes of proteins are usually of different frequencies, the difference in frequency between neighboring modes is so small that, under even slight structural uncertainty that unavoidably exists in structure determination, it can easily vanish and as a result, a mode becomes effectively degenerate with its neighboring modes. This can be easily observed in that some modes seem to disappear and their matching modes cannot be found when the structure used to compute the modes is modified only slightly. We term this degeneracy the effective degeneracy of normal modes. This work is built upon our recent discovery that the vibrational spectrum of globular proteins is universal. The high density of modes observed in the vibrational frequency spectra of proteins renders their normal modes highly susceptible to degeneracy, under even the smallest structural uncertainty. Indeed, we find the degree of degeneracy of modes is proportional to the density of modes in the vibrational spectrum. This means that for modes at the same frequency, degeneracy is more severe for larger proteins. Degeneracy exists also in the modes of coarse-grained models, but to a much lesser extent than those of all-atom models. In closing, we discuss the implications of the effective degeneracy of normal modes: how it may significantly affect the ways in which normal modes are used in various normal modes

  4. Effect of Granulocyte-Macrophage Colony-Stimulating Factor on Chemotherapy-Related Neutropenia in Patients with Non-Hodgkin's Lymphomas-A Phase I/II Study of Dose and Mode of Administration.

    PubMed

    Hovgaard, D J; Nissen, N I

    1991-01-01

    The effect of mammalian glycosylated recombinant granulocyte-macrophage colony-stimulating factor was investigated in 24 patients with newly diagnosed non-Hodgkin's lymphoma in a phase I/II study. All patients received standard chemotherapy with CHOP. RhGM-CSF was administered after the first cycle for 5 days, and at one of four dose levels (2, 4, 8 and 16 μg/kg). Patients were randomized to receive the drug either by continuous intravenous infusion or twice daily as subcutaneous injection. No significant difference in results was observed between subcutaneous administration of rhGM-CSF and continuous i.v. infusion and these patient groups could therefore be combined in the analysis. Administration of rhGM-CSF resulted in a significant dose-dependent increase of total WBC, mainly neutrophils, eosinophils and monocytes. The increase was observed in 18/24 patients, reaching a peak 24-72 (median 24) hours after the start of rhGM-CSF. The CHOP chemotherapy-induced leucocyte nadir occurred on day 12 (mean) compared to day 14 for the 127 historical controls. The WBC nadir values were higher (2.4 ± 1.4) than for historical controls (1.8 ± 1.1) and the leucopenic/neutropenic period was of shorter duration. Following the chemotherapy nadir a more rapid recovery of WBC was seen than in controls. GM-CSF was well tolerated, the side effects were mild and transient, and included myalgias, low grade fever, headache, chest/bone discomfort, nausea, erythema at injection site and superficial phlebitis. The encouraging results of this phase I/II study indicate the need for a prospective controlled study of GM-CSF in chemotherapy of malignant lymphoma.

  5. Mixed mode stress field effect in adhesive fracture

    NASA Technical Reports Server (NTRS)

    Anderson, G. P.; Devries, K. L.; Williams, M. L.

    1974-01-01

    Numerical or analytical analyses were performed on seven different test specimens including blister test, 90-degree peel test, torsion test, and various cone tests. These specimens are in general subjected to complex stress fields having various amounts of Mode I, Mode II, and Mode III loads. The specimens were then constructed using polymethyl methacrylate for the adherends and a transparent polyurethane elastomer (Solithane 113) for the adhesive. This combination permitted direct observation of the bondline as load was applied. Although initial debonds as well as bond end termination singularities were present in all specimens, in some cases the debond did not initiate at the singularity points as would normally have been expected. An explanation for this behavior is presented, as well as a comparison of loading mode effect on those specimens for which the debond did propagate from a bond terminus singular point.

  6. Multiple nucleic acid cleavage modes in divergent type III CRISPR systems

    PubMed Central

    Zhang, Jing; Graham, Shirley; Tello, Agnes; Liu, Huanting; White, Malcolm F.

    2016-01-01

    CRISPR-Cas is an RNA-guided adaptive immune system that protects bacteria and archaea from invading nucleic acids. Type III systems (Cmr, Csm) have been shown to cleave RNA targets in vitro and some are capable of transcription-dependent DNA targeting. The crenarchaeon Sulfolobus solfataricus has two divergent subtypes of the type III system (Sso-IIID and a Cmr7-containing variant of Sso-IIIB). Here, we report that both the Sso-IIID and Sso-IIIB complexes cleave cognate RNA targets with a ruler mechanism and 6 or 12 nt spacing that relates to the organization of the Cas7 backbone. This backbone-mediated cleavage activity thus appears universal for the type III systems. The Sso-IIIB complex is also known to possess a distinct ‘UA’ cleavage mode. The predominant activity observed in vitro depends on the relative molar concentration of protein and target RNA. The Sso-IIID complex can cleave plasmid DNA targets in vitro, generating linear DNA products with an activity that is dependent on both the cyclase and HD nuclease domains of the Cas10 subunit, suggesting a role for both nuclease active sites in the degradation of double-stranded DNA targets. PMID:26801642

  7. Cryogenic Interlaminar Fracture Properties of Woven Glass/Epoxy Composite Laminates Under Mixed-Mode I/III Loading Conditions

    NASA Astrophysics Data System (ADS)

    Miura, Masaya; Shindo, Yasuhide; Takeda, Tomo; Narita, Fumio

    2013-08-01

    We characterize the combined Mode I and Mode III delamination fracture behavior of woven glass fiber reinforced polymer (GFRP) composite laminates at cryogenic temperatures. The eight-point bending plate (8PBP) tests were conducted at room temperature, liquid nitrogen temperature (77 K) and liquid helium temperature (4 K) using a new test fixture. A three-dimensional finite element analysis was also performed to calculate the energy release rate distribution along the delamination front, and the delamination fracture toughnesses were evaluated for various mixed-mode I/III ratios. Furthermore, the microscopic examinations of the fracture surfaces were carried out with scanning electron microscopy (SEM), and the mixed-mode I/III delamination fracture mechanisms in the woven GFRP laminates at cryogenic temperatures were assessed. The fracture properties were then correlated with the observed characteristics.

  8. Characterization of the Edge Crack Torsion (ECT) Test for Mode III Fracture Toughness Measurement of Laminated Composites

    NASA Technical Reports Server (NTRS)

    Ratcliffe, James G.

    2004-01-01

    The edge crack torsion (ECT) test is designed to initiate mode III delamination growth in composite laminates. An ECT specimen is a rectangular laminate, containing an edge delamination at the laminate mid-plane. Torsion load is applied to the specimens, resulting in relative transverse shear sliding of the delaminated faces. The test data reduction schemes are intended to yield initiation values of critical mode III strain energy release rate, G(sub IIIc), that are constant with delamination length. The test has undergone several design changes during its development. The objective of this paper was to determine the suitability of the current ECT test design as a mode III fracture test. To this end, ECT tests were conducted on specimens manufactured from IM7/8552 and specimens made from S2/8552 tape laminates. Several specimens, each with different delamination lengths are tested. Detailed, three-dimensional finite element analyses of the specimens were performed. The analysis results were used to calculate the distribution of mode I, mode II, and mode III strain energy release rate along the delamination front. The results indicated that mode III-dominated delamination growth would be initiated from the specimen center. However, in specimens of both material types, the measured values of G(sub IIIc) exhibited significant dependence on delamination length. Furthermore, there was a large amount of scatter in the data. Load-displacement response of the specimens exhibited significant deviation from linearity before specimen failure. X-radiographs of a sample of specimens revealed that damage was initiated in the specimens prior to failure. Further inspection of the failure surfaces is required to identify the damage and determine that mode III delamination is initiated in the specimens.

  9. Characterization of the Edge Crack Torsion (ECT) Test for Mode III Fracture Toughness Measurement of Laminated Composites

    NASA Technical Reports Server (NTRS)

    Ratcliffe, James G.

    2004-01-01

    The edge crack torsion (ECT) test is designed to initiate mode III delamination growth in composite laminates. The test has undergone several design changes during its development. The objective of this paper was to determine the suitability of the current ECT test design a mode III fracture test. To this end, ECT tests were conducted on specimens manufactured from IM7/8552 and S2/8552 tape laminates. Three-dimensional finite element analyses were performed. The analysis results were used to calculate the distribution of mode I, mode II, and mode III strain energy release rate along the delamination front. The results indicated that mode IIIdominated delamination growth would be initiated from the specimen center. However, in specimens of both material types, the measured values of GIIIc exhibited significant dependence on delamination length. Load-displacement response of the specimens exhibited significant deviation from linearity before specimen failure. X-radiographs of a sample of specimens revealed that damage was initiated in the specimens prior to failure. Further inspection of the failure surfaces is required to identify the damage and determine that mode III delamination is initiated in the specimens.

  10. Dependence of mode I and mixed mode I/III fracture toughness on temperature for a ferritic/martensitic stainless steel

    SciTech Connect

    Li, H.; Jones, R.H.; Gelles, D.S.

    1995-04-01

    The objective is to investigate the dependence of mode I and mixed mode I/III fracture toughness on temperature in the range of {minus}95{degrees}C to 25{degrees}C for a low activation ferritic/martensitic stainless steel (F82-H). Mode I and mixed Mode I/III fracture toughnesses were investigated in the range of {minus}95 to 25{degree}C for a F82-H steel heat-treated in the following way; 1000{degree}C/20 h/air-cooled (AC), 1100{degree}C/7 min/AC, and 700{degree}C/2 h/AC. The results indicate that crack tip plasticity was increased by mixed mode loading, and suggest that at low temperature, mode I fracture toughness is the critical design parameter, but at temperatures above room temperature, expecially concerning fatigure and creep-fatigue crack growth rate, a mixed mode loading may be more harmful than a mode I loading for this steel because a mixed mode loading results in lower fracture toughness and higher crack tip plasticity (or dislocation activity).

  11. Spectral analysis of sung vowels. III. Characteristics of singers and modes of singing.

    PubMed

    Bloothooft, G; Plomp, R

    1986-03-01

    The 1/3-oct spectra of nine different vowels, sung by 14 professional male and female singers in nine different modes of singing, were analyzed to reveal spectral characteristics of individual singers and modes of singing. The main spectral differences between singers could be described in two dimensions characterizing, respectively, differences among male and among female singers. Spectral characteristics of these dimensions suggested that interindividual differences among males, like the average difference between males and females, arise mainly from differences in vocal tract dimensions, whereas interindividual differences among females may have a glottal basis. The spectral characteristics of the modes of singing could be represented for each vowel in two dimensions. Differences among the soft (pianissimo), light, neutral, free, straight, extra vibrato, and loud (fortissimo) modes were mainly due to the spectral effect of vocal effort, which constituted a very dominant first spectral dimension. This dimension essentially reflected the slope of the spectrum. The second dimension mainly described the spectral differences between the dark and pressed modes of singing. A possible explanation of the results in terms of glottal and supraglottal morphological variation is discussed. PMID:3958327

  12. Mode Transitions in Hall Effect Thrusters

    NASA Technical Reports Server (NTRS)

    Sekerak, Michael J.; Longmier, Benjamin W.; Gallimore, Alec D.; Brown, Daniel L.; Hofer, Richard R.; Polk, James E.

    2013-01-01

    Mode transitions have been commonly observed in Hall Effect Thruster (HET) operation where a small change in a thruster operating parameter such as discharge voltage, magnetic field or mass flow rate causes the thruster discharge current mean value and oscillation amplitude to increase significantly. Mode transitions in a 6-kW-class HET called the H6 are induced by varying the magnetic field intensity while holding all other operating parameters constant and measurements are acquired with ion saturation probes and ultra-fast imaging. Global and local oscillation modes are identified. In the global mode, the entire discharge channel oscillates in unison and azimuthal perturbations (spokes) are either absent or negligible. Downstream azimuthally spaced probes show no signal delay between each other and are very well correlated to the discharge current signal. In the local mode, signals from the azimuthally spaced probes exhibit a clear delay indicating the passage of "spokes" and are not well correlated to the discharge current. These spokes are localized oscillations propagating in the ExB direction that are typically 10-20% of the mean value. In contrast, the oscillations in the global mode can be 100% of the mean value. The transition between global and local modes occurs at higher relative magnetic field strengths for higher mass flow rates or higher discharge voltages. The thrust is constant through mode transition but the thrust-to-power decreased by 25% due to increasing discharge current. The plume shows significant differences between modes with the global mode significantly brighter in the channel and the near-field plasma plume as well as exhibiting a luminous spike on thruster centerline. Mode transitions provide valuable insight to thruster operation and suggest improved methods for thruster performance characterization.

  13. A Mixed-Mode (I-II) Fracture Criterion for AS4/8552 Carbon/Epoxy Composite Laminate

    NASA Astrophysics Data System (ADS)

    Karnati, Sidharth Reddy

    A majority of aerospace structures are subjected to bending and stretching loads that introduce peel and shear stresses between the plies of a composite laminate. These two stress components cause a combination of mode I and II fracture modes in the matrix layer of the composite laminate. The most common failure mode in laminated composites is delamination that affects the structural integrity of composite structures. Damage tolerant designs of structures require two types of materials data: mixed-mode (I-II) delamination fracture toughness that predicts failure and delamination growth rate that predicts the life of the structural component. This research focuses determining mixed-mode (I-II) fracture toughness under a combination of mode I and mode II stress states and then a fracture criterion for AS4/8552 composite laminate, which is widely used in general aviation. The AS4/8552 prepreg was supplied by Hexcel Corporation and autoclave fabricated into a 20-ply unidirectional laminate with an artificial delamination by a Fluorinated Ethylene Propylene (FEP) film at the mid-plane. Standard split beam specimens were prepared and tested in double cantilever beam (DCB) and end notched flexure modes to determine mode I (GIC) and II (GIIC) fracture toughnesses, respectively. The DCB specimens were also tested in a modified mixed-mode bending apparatus at GIIm /GT ratios of 0.18, 0.37, 0.57 and 0.78, where GT is total and GIIm is the mode II component of energy release rates. The measured fracture toughness, GC, was found to follow the locus a power law equation. The equation was validated for the present and literature experimental data.

  14. A plane stress finite element model for elastic-plastic mode I/II crack growth

    NASA Astrophysics Data System (ADS)

    James, Mark Anthony

    A finite element program has been developed to perform quasi-static, elastic-plastic crack growth simulations. The model provides a general framework for mixed-mode I/II elastic-plastic fracture analysis using small strain assumptions and plane stress, plane strain, and axisymmetric finite elements. Cracks are modeled explicitly in the mesh. As the cracks propagate, automatic remeshing algorithms delete the mesh local to the crack tip, extend the crack, and build a new mesh around the new tip. State variable mapping algorithms transfer stresses and displacements from the old mesh to the new mesh. The von Mises material model is implemented in the context of a non-linear Newton solution scheme. The fracture criterion is the critical crack tip opening displacement, and crack direction is predicted by the maximum tensile stress criterion at the crack tip. The implementation can accommodate multiple curving and interacting cracks. An additional fracture algorithm based on nodal release can be used to simulate fracture along a horizontal plane of symmetry. A core of plane strain elements can be used with the nodal release algorithm to simulate the triaxial state of stress near the crack tip. Verification and validation studies compare analysis results with experimental data and published three-dimensional analysis results. Fracture predictions using nodal release for compact tension, middle-crack tension, and multi-site damage test specimens produced accurate results for residual strength and link-up loads. Curving crack predictions using remeshing/mapping were compared with experimental data for an Arcan mixed-mode specimen. Loading angles from 0 degrees to 90 degrees were analyzed. The maximum tensile stress criterion was able to predict the crack direction and path for all loading angles in which the material failed in tension. Residual strength was also accurately predicted for these cases.

  15. A direct proofreader–clamp interaction stabilizes the Pol III replicase in the polymerization mode

    PubMed Central

    Jergic, Slobodan; Horan, Nicholas P; Elshenawy, Mohamed M; Mason, Claire E; Urathamakul, Thitima; Ozawa, Kiyoshi; Robinson, Andrew; Goudsmits, Joris M H; Wang, Yao; Pan, Xuefeng; Beck, Jennifer L; van Oijen, Antoine M; Huber, Thomas; Hamdan, Samir M; Dixon, Nicholas E

    2013-01-01

    Processive DNA synthesis by the αɛθ core of the Escherichia coli Pol III replicase requires it to be bound to the β2 clamp via a site in the α polymerase subunit. How the ɛ proofreading exonuclease subunit influences DNA synthesis by α was not previously understood. In this work, bulk assays of DNA replication were used to uncover a non-proofreading activity of ɛ. Combination of mutagenesis with biophysical studies and single-molecule leading-strand replication assays traced this activity to a novel β-binding site in ɛ that, in conjunction with the site in α, maintains a closed state of the αɛθ–β2 replicase in the polymerization mode of DNA synthesis. The ɛ–β interaction, selected during evolution to be weak and thus suited for transient disruption to enable access of alternate polymerases and other clamp binding proteins, therefore makes an important contribution to the network of protein–protein interactions that finely tune stability of the replicase on the DNA template in its various conformational states. PMID:23435564

  16. The equilibrium concentration of hydrogen atoms ahead of a mixed mode I-mode III crack tip in single crystal iron

    SciTech Connect

    Zhang, T.Y.; Hack, J.E.

    1999-01-01

    Calculations of the equilibrium hydrogen concentration profiles about a mixed ode I-mode III crack in single crystal iron were performed. Both material anisotropy and the tetragonal nature of the distortion induced in the iron crystal structure by interstitial hydrogen were incorporated. Results show that, unlike the case of a spherical distortion, a strong coupling exists between the strain field of the interstitial hydrogen and the stress field of the crack for orientations of the crack plane that are not coincident with the cube axes of the lattice. As a result, the predicated enhancement of hydrogen in the crack tip region increases with increasing levels of mode III loading for those orientations. The results may help reconcile conflicting observations concerning the potential role of shear stresses in hydrogen embrittlement and preferential cracking of grains ahead of loaded crack tips in sustained load cracking experiments.

  17. Theoretical and experimental studies on binding mode of 3,5-pyrazoledicarboxylic acid in its new La(III) complex

    NASA Astrophysics Data System (ADS)

    Peica, Niculina; Kostova, Irena; Kiefer, Wolfgang

    2006-06-01

    A new La(III) complex with 3,5-pyrazoledicarboxylic acid (HPy) was synthesized and characterized with elemental analysis, IR, and Raman spectroscopies. Significant differences in the IR and Raman spectra of the complex were observed as compared to the spectra of the ligand. The metal-ligand binding mode was studied on the basis of theoretical and experimental data. B3PW91 and B3LYP methods with 6-311++G ∗∗ and LANL2DZ basis sets were successfully applied to study the molecular and vibrational structures as well as the conformational behavior of the neutral ligand and its new La(III) complex. The theoretical calculations of HPy suggested bidentate binding mode through the carboxylic oxygens. Detailed vibrational analysis of HPy and La(III)-Py systems based on both the calculated and experimental spectra confirmed the suggested metal-ligand binding mode. The density functional theory (DFT) calculated geometries, harmonic vibrational wavenumbers including IR and Raman scattering activities for the ligand and its La(III) complex were in good agreement with the experimental data, a complete vibrational assignment being proposed.

  18. Energetic particle effects on global MHD modes

    SciTech Connect

    Cheng, C.Z.

    1990-01-01

    The effects of energetic particles on MHD type modes are studied by analytical theories and the nonvariational kinetic-MHD stability code (NOVA-K). In particular we address the problems of (1) the stabilization of ideal MHD internal kink modes and the excitation of resonant fishbone'' internal modes and (2) the alpha particle destabilization of toroidicity-induced Alfven eigenmodes (TAE) via transit resonances. Analytical theories are presented to help explain the NOVA-K results. For energetic trapped particles generated by neutral-beam injection (NBI) or ion cyclotron resonant heating (ICRH), a stability window for the n=1 internal kink mode in the hot particle beat space exists even in the absence of core ion finite Larmor radius effect (finite {omega}{sub *i}). On the other hand, the trapped alpha particles are found to resonantly excite instability of the n=1 internal mode and can lower the critical beta threshold. The circulating alpha particles can strongly destabilize TAE modes via inverse Landau damping associated with the spatial gradient of the alpha particle pressure. 23 refs., 5 figs.

  19. Electromagnetic effects on geodesic acoustic modes

    SciTech Connect

    Bashir, M. F.; Smolyakov, A. I.; Elfimov, A. G.; Melnikov, A. V.; Murtaza, G.

    2014-08-15

    By using the full electromagnetic drift kinetic equations for electrons and ions, the general dispersion relation for geodesic acoustic modes (GAMs) is derived incorporating the electromagnetic effects. It is shown that m = 1 harmonic of the GAM mode has a finite electromagnetic component. The electromagnetic corrections appear for finite values of the radial wave numbers and modify the GAM frequency. The effects of plasma pressure β{sub e}, the safety factor q, and the temperature ratio τ on GAM dispersion are analyzed.

  20. Mode I and mixed I/III crack initiation and propagation behavior of V-4Cr-4Ti alloy at 25{degrees}C

    SciTech Connect

    Li, H.X.; Kurtz, R.J.; Jones, R.H.

    1997-04-01

    The mode I and mixed-mode I/III fracture behavior of the production-scale heat (No. 832665) of V-4Cr-4Ti has been investigated at 25{degrees}C using compact tension (CT) specimens for a mode I crack and modified CT specimens for a mixed-mode I/III crack. The mode III to mode I load ratio was 0.47. Test specimens were vacuum annealed at 1000{degrees}C for 1 h after final machining. Both mode I and mixed-mode I/III specimens were fatigue cracked prior to J-integral testing. It was noticed that the mixed-mode I/III crack angle decreased from an initial 25 degrees to approximately 23 degrees due to crack plane rotation during fatigue cracking. No crack plane rotation occurred in the mode I specimen. The crack initiation and propagation behavior was evaluated by generating J-R curves. Due to the high ductility of this alloy and the limited specimen thickness (6.35 mm), plane strain requirements were not met so valid critical J-integral values were not obtained. However, it was found that the crack initiation and propagation behavior was significantly different between the mode I and the mixed-mode I/III specimens. In the mode I specimen crack initiation did not occur, only extensive crack tip blunting due to plastic deformation. During J-integral testing the mixed-mode crack rotated to an increased crack angle (in contrast to fatigue precracking) by crack blunting. When the crack initiated, the crack angle was about 30 degrees. After crack initiation the crack plane remained at 30 degrees until the test was completed. Mixed-mode crack initiation was difficult, but propagation was easy. The fracture surface of the mixed-mode specimen was characterized by microvoid coalescence.

  1. A streamlined failure mode and effects analysis

    SciTech Connect

    Ford, Eric C. Smith, Koren; Terezakis, Stephanie; Croog, Victoria; Gollamudi, Smitha; Gage, Irene; Keck, Jordie; DeWeese, Theodore; Sibley, Greg

    2014-06-15

    Purpose: Explore the feasibility and impact of a streamlined failure mode and effects analysis (FMEA) using a structured process that is designed to minimize staff effort. Methods: FMEA for the external beam process was conducted at an affiliate radiation oncology center that treats approximately 60 patients per day. A structured FMEA process was developed which included clearly defined roles and goals for each phase. A core group of seven people was identified and a facilitator was chosen to lead the effort. Failure modes were identified and scored according to the FMEA formalism. A risk priority number,RPN, was calculated and used to rank failure modes. Failure modes with RPN > 150 received safety improvement interventions. Staff effort was carefully tracked throughout the project. Results: Fifty-two failure modes were identified, 22 collected during meetings, and 30 from take-home worksheets. The four top-ranked failure modes were: delay in film check, missing pacemaker protocol/consent, critical structures not contoured, and pregnant patient simulated without the team's knowledge of the pregnancy. These four failure modes hadRPN > 150 and received safety interventions. The FMEA was completed in one month in four 1-h meetings. A total of 55 staff hours were required and, additionally, 20 h by the facilitator. Conclusions: Streamlined FMEA provides a means of accomplishing a relatively large-scale analysis with modest effort. One potential value of FMEA is that it potentially provides a means of measuring the impact of quality improvement efforts through a reduction in risk scores. Future study of this possibility is needed.

  2. Characterization of the apoLp-III/LPS complex: insight in the mode of binding interaction

    PubMed Central

    Oztug, Merve; Martinon, Daisy; Weers, Paul M.M.

    2012-01-01

    Apolipoproteins are able to associate with lipopolysaccharides (LPS), potentially providing protection against septic shock. To gain insight in the molecular details of this binding interaction, apolipophorin III (apoLp-III) from Galleria mellonella was used as a model. The binding of apoLp-III to LPS was optimal around 37–40 °C, close to the LPS phase transition temperature. ApoLp-III formed complexes with LPS from E. coli (serotype O55:B5) with a diameter of 24 nm, a molecular weight of ~390 kDa, containing four molecules of apoLp-III and 24 molecules of LPS. The LPS-bound form of the protein was substantially more resistant to guanidine-induced denaturation compared to unbound protein. The denaturation profile displayed a multiphase character with a steep drop in secondary structure between 0–1 M guanidine, and a slower decrease above 1 M guanidine HCl. In contrast, apoLp-III bound to detoxified LPS was only slightly more resistant to guanidine HCl induced denaturation compared to unbound protein. Analysis of size-exclusion FPLC elution profiles of mixtures of apoLp-III with LPS or detoxified LPS indicated a much weaker binding interaction with detoxified LPS compared to intact LPS. These results indicate that apoLp-III initially interacts with exposed carbohydrate regions, but that the lipid A region is required for a more stable LPS binding interaction. PMID:22779761

  3. Period-Luminosity relations derived from the OGLE-III first-overtone mode Cepheids in the Magellanic Clouds

    NASA Astrophysics Data System (ADS)

    Bhardwaj, Anupam; Ngeow, Chow-Choong; Kanbur, Shashi M.; Singh, Harinder P.

    2016-06-01

    We present multiband Period-Luminosity (PL) relations for first-overtone mode Cepheids in the Small Magellanic Cloud (SMC). We derive optical band PL relations and the Wesenheit function using VI mean magnitudes from the Optical Gravitational Lensing Experiment (OGLE-III) survey. We cross-match OGLE-III first-overtone mode Cepheids to the 2MASS and SAGE-SMC catalogues to derive PL relations at near-infrared (JHKs) and mid-infrared (3.6 and 4.5 μm) wavelengths. We test for possible non-linearities in these PL relations using robust statistical tests and find a significant break only in the optical band PL relations at 2.5 d for first-overtone mode Cepheids. We do not find statistical evidence for a non-linearity in these PL relations at 1 d. The multiband PL relations for fundamental-mode Cepheids in the SMC also exhibit a break at 2.5 d. We suggest that the period break around 2.5 d is related to sharp changes in the light-curve parameters for SMC Cepheids. We also derive new optical and mid-infrared band PL relations for first-overtone mode Cepheids in the Large Magellanic Cloud (LMC). We compare multiband PL relations for first-overtone mode Cepheids in the Magellanic Clouds and find a significant difference in the slope of the V-band PL relations but not for I-band PL relations. The slope of PL relations are found to be consistent in most of the infrared bands. A relative distance modulus of Δμ = 0.49 ± 0.02 mag between the two clouds is estimated using multiband PL relations for the first-overtone mode Cepheids in the SMC and LMC.

  4. Evaluation of the split cantilever beam for mode III delamination testing

    NASA Technical Reports Server (NTRS)

    Martin, Roderick, H.

    1991-01-01

    A test rig for testing a thick split cantilever beam for scissoring delamination (mode 3) fracture toughness was developed. A 3-D finite element analysis was conducted on the test specimen to determine the strain energy release rate, G, distribution along the delamination front. The virtual crack closure technique was used to calculate the G components resulting from interlaminar tension, GI, interlaminar sliding shear, GII, and interlaminar tearing shear, GIII. The finite element analysis showed that at the delamination front no GI component existed, but a GII component was present in addition to a GIII component. Furthermore, near the free edges, the GII component was significantly higher than the GIII component. The GII/GIII ratio was found to increase with delamination length but was insensitive to the beam depth. The presence of GII at the delamination front was verified experimentally by examination of the failure surfaces. At the center of the beam, where the failure was in mode 3, there was significant fiber bridging. However, at the edges of the beam where the failure was in mode 3, there was no fiber bridging and mode 2 shear hackles were observed. Therefore, it was concluded that the split cantilever beam configuration does not represent a pure mode 3 test. The experimental work showed that the mode 2 fracture toughness, GIIc, must be less than the mode 3 fracture toughness, GIIIc. Therefore, a conservative approach to characterizing mode 3 delamination is to equate GIIIc to GIIc.

  5. Gravitational wave quasinormal mode from Population III massive black hole binaries in various models of population synthesis

    NASA Astrophysics Data System (ADS)

    Kinugawa, Tomoya; Nakano, Hiroyuki; Nakamura, Takashi

    2016-10-01

    Focusing on the remnant black holes after merging binary black holes, we show that ringdown gravitational waves of Population III binary black hole mergers can be detected at the rate of 5.9-500 events yr(SFR/(10M yr Mpc))ṡ([f/(1+f)]/0.33) for various parameters and functions. This rate is estimated for events with SNR>8 for second-generation gravitational wave detectors such as KAGRA. Here, SFR and f are the peak value of the Population III star formation rate and the fraction of binaries, respectively. When we consider only events with SNR>35, the event rate becomes 0.046-4.21 events yr(SFR/(10M yr Mpc))ṡ([f/(1+f)]/0.33). This suggest that for a remnant black hole spin of q>0.95 we have an event rate of quasinormal modes with SNR>35 of less than 0.037 events yr(SFR/(10M yr Mpc))ṡ([f/(1+f)]/0.33), while it is 3-30 events yr(SFR/(10M yr Mpc))ṡ([f/(1+f)]/0.33) for third-generation detectors such as the Einstein Telescope. If we detect many Population III binary black hole mergers, it may be possible to constrain the Population III binary evolution paths not only by the mass distribution but also by the spin distribution.

  6. Selectivity Enhancement for Chloride Ion by In(III)-Porphyrin-Based Polymeric Membrane Electrode Operated in Pulsed Chronopotentiometric Mode

    PubMed Central

    Gemene, Kebede L.; Meyerhoff, Mark E.

    2013-01-01

    A robust selectivity enhancement of an In(III)-porphyrin ionophore-based chloride-selective electrode under pulsed chronopotentiometric measurement mode that enables the detection of chloride ions in the presence of a normally interfering concentration of salicylate ions is described. This enhancement is achieved by the rapid depletion of the surface concentration of the more dilute lipophilic anion during an initial anodic current pulse period due to extraction of this preferred anion into the membrane phase. Measurement of chloride with a detection limit of 8 mM and near Nernstian response slope in the presence of 1 mM salicylate is possible using the pulstrode method. PMID:23355767

  7. Experiments on fracture toughness of thick-wall cylinder for modes I, II, III

    SciTech Connect

    Saegusa, T.; Urabe, N.; Ito, C.; Shirai, K.; Kosaki, A.

    1999-07-01

    There have been few data on fracture toughness for Mode 2 and 3 as compared with those for Mode 1. Experimental data on fracture toughness of plates made of ductile cast iron (ASTM A874-89) and forged steel (ASME SA350 LF5 C1.1) were obtained at a temperature range from 77K to 293K for Mode 1, 2 and 3. The results showed: J{sub IC} < J{sub IIC} < J{sub IIIC}, and K{sub IC} < K{sub IIC} K{sub IIIC}. Integrity of a thick-wall cylinder with artificial flaw was demonstrated against brittle fracture at 233K for Mode 1, 2 and 3, which is one of the design requirements of containers shipping radioactive materials.

  8. A Modified Edge Crack Torsion Test for Measurement of Mode III Fracture Toughness of Laminated Tape Composites

    NASA Technical Reports Server (NTRS)

    Czabaj, Michael W.; Davidson, Barry D.; Ratcliffe, James G.

    2016-01-01

    Modifications to the edge crack torsion (ECT) test are studied to improve the reliability of this test for measuring the mode-III fracture toughness, G (sub IIIc), of laminated tape fiber-reinforced polymeric (FRP) composites. First, the data reduction methods currently used in the ECT test are evaluated and deficiencies in their accuracy are discussed. An alternative data reduction technique, which uses a polynomial form to represent ECT specimen compliance solution, is evaluated and compared to FEA (finite element analysis) results. Second, seven batches of ECT specimens are tested, each batch containing specimens with a preimplanted midplane edge delamination and midplane plies with orientations of plus theta divided by minus theta, with theta ranging from 0 degrees to 90 degrees in 15-degree increments. Tests on these specimens show that intralaminar cracking occurs in specimens from all batches except for which theta = 15 degrees and 30 degrees. Tests on specimens of these two batches are shown to result in mode-III delamination growth at the intended ply interface. The findings from this study are encouraging steps towards the use of the ECT test as a standardized method for measuring G (sub IIIc), although further modification to the data reduction method is required to make it suitable for use as part of a standardized test method.

  9. 25 CFR 291.15 - How long do Class III gaming procedures remain in effect?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false How long do Class III gaming procedures remain in effect... ENTERPRISES CLASS III GAMING PROCEDURES § 291.15 How long do Class III gaming procedures remain in effect? Class III gaming procedures remain in effect for the duration specified in the procedures or...

  10. 25 CFR 291.15 - How long do Class III gaming procedures remain in effect?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false How long do Class III gaming procedures remain in effect... ENTERPRISES CLASS III GAMING PROCEDURES § 291.15 How long do Class III gaming procedures remain in effect? Class III gaming procedures remain in effect for the duration specified in the procedures or...

  11. (-)-Carvone: antispasmodic effect and mode of action.

    PubMed

    Souza, Fábia Valéria M; da Rocha, Marcelly Barbosa; de Souza, Damião P; Marçal, Rosilene Moretti

    2013-03-01

    (-)-Carvone is a monoterpene ketone found in spearmint (Mentha spicata var. crispa) essential oil that is widely used as an odor and flavor additive. An intestinal antispasmodic effect was recently reported for (-)-carvone, and it has been shown to be more potent than its (+)-antipode. The mechanism of (-)-carvone action in the intestines has not been investigated. To gain a better understanding of the (-)-carvone antispasmodic effect, we investigated its pharmacological effects in the guinea pig ileum. Terminal portions of the ileum were mounted for isotonic contraction recordings. The effect of (-)-carvone was compared with that of the classical calcium channel blocker (CCB) verapamil. In isolated ileal smooth muscle, (-)-carvone did not produce direct contractile or relaxation responses and did not modify electrically elicited contractions or low K(+)-evoked contractions. The submaximal contractions induced by histamine (p<0.001), BaCl2 (p<0.05), and carbachol (p<0.01) were significantly reduced by (-)-carvone. The contractile response elicited by high concentrations of carbachol was reduced but not abolished by (-)-carvone. No additive action was detected with co-incubation of (-)-carvone and verapamil on carbachol-induced contraction. (-)-Carvone reduced the contraction induced by high K(+) and was almost 100 times more potent than verapamil. Thus, (-)-carvone showed a typical and potent CCB-like action. Many effects described for both (-)-carvone and spearmint oil can be explained as a CCB-like mode of action.

  12. Drift effects on electromagnetic geodesic acoustic modes

    NASA Astrophysics Data System (ADS)

    Sgalla, R. J. F.

    2015-02-01

    A two fluid model with parallel viscosity is employed to derive the dispersion relation for electromagnetic geodesic acoustic modes (GAMs) in the presence of drift (diamagnetic) effects. Concerning the influence of the electron dynamics on the high frequency GAM, it is shown that the frequency of the electromagnetic GAM is independent of the equilibrium parallel current but, in contrast with purely electrostatic GAMs, significantly depends on the electron temperature gradient. The electromagnetic GAM may explain the discrepancy between the f ˜ 40 kHz oscillation observed in tokamak TCABR [Yu. K. Kuznetsov et al., Nucl. Fusion 52, 063044 (2012)] and the former prediction for the electrostatic GAM frequency. The radial wave length associated with this oscillation, estimated presently from this analytical model, is λr ˜ 25 cm, i.e., an order of magnitude higher than the usual value for zonal flows (ZFs).

  13. Drift effects on electromagnetic geodesic acoustic modes

    SciTech Connect

    Sgalla, R. J. F.

    2015-02-15

    A two fluid model with parallel viscosity is employed to derive the dispersion relation for electromagnetic geodesic acoustic modes (GAMs) in the presence of drift (diamagnetic) effects. Concerning the influence of the electron dynamics on the high frequency GAM, it is shown that the frequency of the electromagnetic GAM is independent of the equilibrium parallel current but, in contrast with purely electrostatic GAMs, significantly depends on the electron temperature gradient. The electromagnetic GAM may explain the discrepancy between the f ∼ 40 kHz oscillation observed in tokamak TCABR [Yu. K. Kuznetsov et al., Nucl. Fusion 52, 063044 (2012)] and the former prediction for the electrostatic GAM frequency. The radial wave length associated with this oscillation, estimated presently from this analytical model, is λ{sub r} ∼ 25 cm, i.e., an order of magnitude higher than the usual value for zonal flows (ZFs)

  14. The Distribution of Scaled Scores and Possible Floor Effects on the WISC-III and WAIS-III

    ERIC Educational Resources Information Center

    Whitaker, Simon; Wood, Christopher

    2008-01-01

    Objective: It has been suggested that, as the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) and the Wechsler Intelligence Scale for Children-Third Edition (WISC-III) give a scaled score of one even if a client scores a raw score of zero, these assessments may have a hidden floor effect at low IQ levels. The study looked for…

  15. Effect of thrombin and endotoxin on the in vivo metabolism of antithrombin III (AT III) in dogs

    SciTech Connect

    Tanaka, H.; Kobayashi, N.; Maekawa, T.

    1985-11-01

    Effect of thrombin and endotoxin on the metabolism of I-125-labelled canine AT III was studied in mongrel dogs. Under control condition, mean total amount of intravascular AT III with standard deviation was 23.4 +/- 2.4 mg/kg, plasma half life of i.v. injected I-125-AT III was 1.7 +/- 0.2 days, and the fractional catabolic flux (j3x) was 16.3 +/- 1.6 mg/kg/day. The total amount of intra- and extra-vascular AT III was 36.0 +/- 0.34 mg/kg. Neither a 3 hour infusion of a small dose (30 units/kg/hr) of thrombin nor i.v. injection of a large amount of thrombin (5,000-15,000 units/day) with heparin significantly affected AT III metabolism except for a transient decrease in AT III concentration in the latter case, although decrease in plasma fibrinogen concentration and platelet count was observed in both cases. Two injections with 200 micrograms/kg of endotoxin resulted in an evident acceleration of AT III metabolism with significant decrease in the plasma AT III, fibrinogen concentrations and platelet count. More marked changes in AT III metabolism were induced by a single infusion with 1 mg/kg of endotoxin. Changes in hemostatic system coincided with those observed in DIC.

  16. Transfer-printing-based integration of single-mode waveguide-coupled III-V-on-silicon broadband light emitters.

    PubMed

    De Groote, Andreas; Cardile, Paolo; Subramanian, Ananth Z; Fecioru, Alin M; Bower, Christopher; Delbeke, Danae; Baets, Roel; Roelkens, Günther

    2016-06-27

    We present the first III-V opto-electronic components transfer printed on and coupled to a silicon photonic integrated circuit. Thin InP-based membranes are transferred to an SOI waveguide circuit, after which a single-spatial-mode broadband light source is fabricated. The process flow to create transfer print-ready coupons is discussed. Aqueous FeCl3 at 5°C was found to be the best release agent in combination with the photoresist anchoring structures that were used. A thin DVS-BCB layer provides a strong bond, accommodating the post-processing of the membranes. The resulting optically pumped LED has a 3 dB bandwidth of 130 nm, comparable to devices realized using a traditional die-to-wafer bonding method. PMID:27410539

  17. Mode Contributions to the Casimir Effect

    NASA Astrophysics Data System (ADS)

    Intravaia, F.; Henkel, C.

    2010-04-01

    Applying a sum-over-modes approach to the Casimir interaction between two plates with finite conductivity, we isolate and study the contributions of surface plasmons and Foucault (eddy current) modes. We show in particular that for the TE-polarization eddy currents provide a repulsive force that cancels, at high temperatures, the Casimir free energy calculated with the plasma model.

  18. Local mode of motions in amorphous solid. III. Contribution of hydrogen bonds in D-sorbitol

    NASA Astrophysics Data System (ADS)

    Naoki, Motosuke; Ujita, Koji

    1993-11-01

    Dielectric properties of the local mode of motions (the β relaxation process) in two D-sorbitol glasses are presented as a function of temperature and pressure. The glasses were vitrified from the liquid by isobaric cooling at a rate of -0.2 K/min under 0.1 and 78.5 MPa. The following results are different from those observed in molecular and polymer glasses: the relaxation magnitude of the higher-density glass vitrified under 78.5 MPa is larger than that of the lower-density glass vitrified under the atmospheric pressure; the distribution of the relaxation time of the higher-density glass is narrower than that of the lower-density glass; and the relaxation magnitude of each glass appears to increase slightly with pressure. The results are interpreted by the difference in the distribution of intermolecular hydrogen bonds frozen-in at the vitrification points. It is also suggested that the hydrogen bonds in the glasses may be slightly decomposed and/or weakened by external pressure.

  19. a Mossbauer Effect Study of Iron(iii) Dithiocarbamates.

    NASA Astrophysics Data System (ADS)

    Fiddy, Judith Mary

    Available from UMI in association with The British Library. Ever since the pioneering work of Cambi iron(III) trisdithiocarbamates, which have the formula Fe(R _2NCS_2]_3 where R is an alkyl or an aryl group, have formed the basis for understanding spin-state equilibria in iron(III) complexes. Magnetic and infrared studies clearly indicate equilibrium between the high-spin and low-spin states. The Mossbauer spectra, however, show only a single component, indicating rapid relaxation between the two spin states on the Mossbauer timescale. It has been assumed that the spectral parameters are therefore a function of the relative spin-state populations. In this thesis, the results of Mossbauer experiments carried out on a series of iron(III) trisdithiocarbamates with various organic substituents, known to give a range of high-spin and low-spin state populations at room temperature, are presented. An iron(III) bisdithiocarbamate complex, Fe^{57} ((C_5 H_{10})_2NCS _2]_2NCS, was also investigated. The samples were studied at temperatures from 1.3K to 295K, and at pressures between atmospheric pressure and 80kbar at room temperature only. It was found that, in fact, the spin-equilibrium plays only a minor role in determining the Mossbauer spectra of the trisdithiocarbamate compounds. The effects of spin -state relaxation on the temperature dependence of the spectra are, in general, masked by those of slow paramagnetic relaxation which, in contrast to the effects of the spin-equilibrium, are marked and different for each compound. By fitting the spectra to models of paramagnetic relaxation the temperature dependence of the relaxation rates and possible directions of the magnetic hyperfine field relative to the major axis of the electric field gradient were found. The pressure dependence of the spectra was found to be rather similar for all the compounds, the main differences being in the widths and in the asymmetry of the areas of the spectral lines. Both these effects can

  20. Period-Luminosity Relations Derived from the OGLE-III Fundamental Mode Cepheids. II. the Small Magellanic Cloud Cepheids

    NASA Astrophysics Data System (ADS)

    Ngeow, Chow-Choong; Kanbur, Shashi M.; Bhardwaj, Anupam; Singh, Harinder P.

    2015-07-01

    In this paper we present multi-band period-luminosity (P-L) relations for fundamental mode Cepheids in the SMC. The optical VI-band mean magnitudes for these SMC Cepheids were taken from the third phase of the Optical Gravitational Lensing Experiment (OGLE-III) catalog. We also matched the OGLE-III SMC Cepheids to 2MASS and SAGE-SMC catalog to derive mean magnitudes in the JHK-bands and the four Spitzer IRAC bands, respectively. All photometry was corrected for extinction by adopting Zaritsky’s extinction map. Cepheids with periods smaller than ˜2.5 days were removed from the sample. In addition to the extinction corrected P-L relations in nine filters from optical to infrared, we also derived the extinction-free Wesenheit function for these Cepheids. We tested the nonlinearity of these SMC P-L relations (except the 8.0 μ {{m}}-band P-L relation) at 10 days: none of the P-L relations show statistically significant evidence of nonlinearity. When compared to the P-L relations in the LMC, the t-test results revealed that there is a difference between the SMC/LMC P-L slopes only in the V- and J-band. Further, we found excellent agreement between the SMC/LMC Wesenheit P-L slope. The difference in LMC and SMC Period-Wesenheit relation LMC and SMC zero points was found to be {{Δ }}μ =0.483+/- 0.015 mag. This amounts to a difference in distance modulus between the LMC and SMC.

  1. Technology-Enhanced Courses and a Mode III Organization of Instructional Work

    ERIC Educational Resources Information Center

    Rhoades, Gary

    2007-01-01

    Although information technology is increasingly used to deliver distance and conventional courses, there have been few studies of the effect of technology-enhanced education on the organization and purposes of academics' instructional work. I explore this issue in undergraduate and masters level education through the vehicle of case analyses of…

  2. Composed planar Hall effect sensors with dual-mode operation

    NASA Astrophysics Data System (ADS)

    Mor, Vladislav; Roy, Debangsu; Schultz, Moty; Klein, Lior

    2016-02-01

    We present a composed planar Hall effect sensor with two modes of operation: (a) an ON mode where the composed sensor responds to magnetic field excitations similarly to the response of a regular planar Hall effect sensor, and (b) an OFF mode where the response is negligible. The composed planar Hall effect sensor switches from the OFF mode to the ON mode when it is exposed to a magnetic field which exceeds a certain threshold determined by the sensor design. The features of this sensor make it useful as a switch triggered by magnetic field and as a sensing device with memory, as its mode of operation indicates exposure to a magnetic field larger than a certain threshold without the need to be activated during the exposure itself.

  3. Analysis of the Effects of Three Modes of Head Start Delivery. Head Start Delivery Modes Project: Final Report.

    ERIC Educational Resources Information Center

    Peters, Donald L.; And Others

    This study analyzed the critical features of three delivery modes for Head Start services in order to: (1) compare the effects of different delivery modes on the immediate outcomes for children and parents; and (2) explore the pattern of effects both within and across modes to ascertain how the process works. The first mode represented the most…

  4. Adamantyl-group containing mixed-mode acrylamide-based continuous beds for capillary electrochromatography. Part III. Optimization of the chromatographic efficiency.

    PubMed

    Al-Massaedh, Ayat Allah; Pyell, Ute

    2014-01-17

    In a previous article we described the synthesis of amphiphilic monolithic stationary phases by in situ free radical copolymerization of cyclodextrin-solubilized N-adamantyl acrylamide, piperazinediacrylamide, methacrylamide and vinylsulfonic acid in aqueous medium in pre-treated fused silica capillaries of 100μ.m I.D. In this work, a series of N-adamantyl-group containing acrylamide-based continuous beds is synthesized under variation of different synthesis parameters. The studied synthesis parameters are (i) concentration of the lyotropic salt ammonium sulfate, (ii) concentration of the initiator ammonium persulfate, and (iii) concentration of the negatively charged monomer vinylsulfonic acid in the polymerization mixture. The influence of the synthesis parameters on the chromatographic efficiency is studied under isocratic conditions for a homologues series of alkylphenones in the reversed-phase mode at constant composition of the mobile phase via capillary electrochromatography with varied electric field strength. With varied concentration of the lyotropic salt ammonium sulfate or varied concentration of the initiator ammonium persulfate in the polymerization mixture, a strong impact on the chromatographic efficiency is observed, while there is only a minor influence when varying the molar fraction of the charged monomer VSA. The absence of a significant influence of extra-column band broadening effects on the determined efficiency is confirmed. There is a good repeatability (with respect to capillary-to-capillary variation and run-to-run variation) reached for the theoretical plate heights obtained for DMF and selected alkylphenones in the reversed-phase mode. PMID:24296296

  5. Plasmon modes of metallic nanowires including quantum nonlocal effects

    SciTech Connect

    Moradi, Afshin

    2015-03-15

    The properties of electrostatic surface and bulk plasmon modes of cylindrical metallic nanowires are investigated, using the quantum hydrodynamic theory of plasmon excitation which allows an analytical study of quantum tunneling effects through the Bohm potential term. New dispersion relations are obtained for each type of mode and their differences with previous treatments based on the standard hydrodynamic model are analyzed in detail. Numerical results show by considering the quantum effects, as the value of wave number increases, the surface modes are slightly red-shifted first and then blue-shifted while the bulk modes are blue-shifted.

  6. Effective As(III) Removal by A Multi-Charged Hydroacid Complex Draw Solute Facilitated Forward Osmosis-Membrane Distillation (FO-MD) Processes.

    PubMed

    Ge, Qingchun; Han, Gang; Chung, Tai-Shung

    2016-03-01

    Effective removal of As(III) from water by an oxalic acid complex with the formula of Na3[Cr(C2O4)3] (Na-Cr-OA) is demonstrated via an forward osmosis-membrane distillation (FO-MD) hybrid system in this study. Na-Cr-OA first proved its superiority as a draw solute with high water fluxes and negligible reverse fluxes in FO, then a systematic investigation of the Na-Cr-OA promoted FO process was conducted to ascertain the factors in As(III) removal. Relatively high water fluxes of 28 LMH under the FO mode and 74 LMH under the pressure retarded osmosis (PRO) mode were achieved when using a 1000 ppm As(III) solution as the feed and 1.0 M Na-Cr-OA as the draw solution at 60 °C. As(III) removal with a water recovery up to 21.6% (FO mode) and 48.3% (PRO mode) were also achieved in 2 h. An outstanding As(III) rejection with 30-3000 μg/L As(III) in the permeate was accomplished when As(III) feed solutions varied from 5 × 10(4) to 1 × 10(6) μg/L, superior to the best FO performance reported for As(III) removal. Incorporating MD into FO not only makes As(III) removal sustainable by reconcentrating the Na-Cr-OA solution simultaneously, but also reduces the As(III) concentration below 10 μg/L in the product water, meeting the WHO standard. PMID:26822310

  7. Effective As(III) Removal by A Multi-Charged Hydroacid Complex Draw Solute Facilitated Forward Osmosis-Membrane Distillation (FO-MD) Processes.

    PubMed

    Ge, Qingchun; Han, Gang; Chung, Tai-Shung

    2016-03-01

    Effective removal of As(III) from water by an oxalic acid complex with the formula of Na3[Cr(C2O4)3] (Na-Cr-OA) is demonstrated via an forward osmosis-membrane distillation (FO-MD) hybrid system in this study. Na-Cr-OA first proved its superiority as a draw solute with high water fluxes and negligible reverse fluxes in FO, then a systematic investigation of the Na-Cr-OA promoted FO process was conducted to ascertain the factors in As(III) removal. Relatively high water fluxes of 28 LMH under the FO mode and 74 LMH under the pressure retarded osmosis (PRO) mode were achieved when using a 1000 ppm As(III) solution as the feed and 1.0 M Na-Cr-OA as the draw solution at 60 °C. As(III) removal with a water recovery up to 21.6% (FO mode) and 48.3% (PRO mode) were also achieved in 2 h. An outstanding As(III) rejection with 30-3000 μg/L As(III) in the permeate was accomplished when As(III) feed solutions varied from 5 × 10(4) to 1 × 10(6) μg/L, superior to the best FO performance reported for As(III) removal. Incorporating MD into FO not only makes As(III) removal sustainable by reconcentrating the Na-Cr-OA solution simultaneously, but also reduces the As(III) concentration below 10 μg/L in the product water, meeting the WHO standard.

  8. III-V nanowire growth mechanism: V/III ratio and temperature effects.

    PubMed

    Dayeh, Shadi A; Yu, Edward T; Wang, Deli

    2007-08-01

    We have studied the dependence of Au-assisted InAs nanowire (NW) growth on InAs(111)B substrates as a function of substrate temperature and input V/III precursor ratio using organometallic vapor-phase epitaxy. Temperature-dependent growth was observed within certain temperature windows that are highly dependent on input V/III ratios. This dependence was found to be a direct consequence of the drop in NW nucleation and growth rate with increasing V/III ratio at a constant growth temperature due to depletion of indium at the NW growth sites. The growth rate was found to be determined by the local V/III ratio, which is dependent on the input precursor flow rates, growth temperature, and substrate decomposition. These studies advance understanding of the key processes involved in III-V NW growth, support the general validity of the vapor-liquid-solid growth mechanism for III-V NWs, and improve rational control over their growth morphology. PMID:17608541

  9. Mod 1 wind turbine generator failure modes and effects analysis

    NASA Technical Reports Server (NTRS)

    1979-01-01

    A failure modes and effects analysis (FMEA) was directed primarily at identifying those critical failure modes that would be hazardous to life or would result in major damage to the system. Each subsystem was approached from the top down, and broken down to successive lower levels where it appeared that the criticality of the failure mode warranted more detail analysis. The results were reviewed by specialists from outside the Mod 1 program, and corrective action taken wherever recommended.

  10. The Modes of Action of ChiIII, a Chitinase from Mushroom Coprinopsis cinerea, Shift with Changes in the Length of GlcNAc Oligomers.

    PubMed

    Niu, Xin; Liu, Cui-Cui; Xiong, Yuan-Jing; Yang, Ming-Mei; Ma, Fei; Liu, Zhong-Hua; Yuan, Sheng

    2016-09-21

    A putative class III endochitinase (ChiIII) was reported previously to be expressed dominantly in fruiting bodies of Coprinopsis cinerea, and its expression levels increased with the maturation of the fruiting bodies. This paper further reports that ChiIII is a novel chitinase with exo- and endoactivities. When the substrate was (GlcNAc)3-5, ChiIII exhibited exoactivity, releasing GlcNAc processively from the reducing end of (GlcNAc)3-5; when the substrate was (GlcNAc)6-7, the activity of ChiIII shifted to an endoacting enzyme, randomly splitting chitin oligosaccharides to various shorter oligosaccharides. This shift in the mode of action of ChiIII may be related to its stronger hydrolytic capacity to degrade chitin in fungal cell walls. The predicted structure of ChiIII shows that it lacks the α+β domain insertion; however, its substrate binding cleft seems to be deeper than that of common endochitinases but shallower and more open than that of common exochitinases, which may be related to its exo- and endohydrolytic activities. PMID:27573573

  11. Complexation of Nd(III) with tetraborate ion and its effect on actinide (III) solubility in WIPP brine

    SciTech Connect

    Borkowski, Marian; Richmann, Michael K; Reed, Donald T; Yongliang, Xiong

    2010-01-01

    The potential importance of tetraborate complexation on lanthanide(III) and actinide(III) solubility is recognized in the literature but a systematic study of f-element complexation has not been performed. In neodymium solubility studies in WIPP brines, the carbonate complexation effect is not observed since tetraborate ions form a moderately strong complex with neodymium(III). The existence of these tetraborate complexes was established for low and high ionic strength solutions. Changes in neodymium(III) concentrations in undersaturation experiments were used to determine the neodymium with tetraborate stability constants as a function of NaCl ionic strength. As very low Nd(III) concentrations have to be measured, it was necessary to use an extraction pre-concentration step combined with ICP-MS analysis to extend the detection limit by a factor of 50. The determined Nd(III) with borate stability constants at infinite dilution and 25 C are equal to log {beta}{sub 1} = 4.55 {+-} 0.06 using the SIT approach, equal to log {beta}{sub 1} = 4.99 {+-} 0.30 using the Pitzer approach, with an apparent log {beta}{sub 1} = 4.06 {+-} 0.15 (in molal units) at I = 5.6 m NaCl. Pitzer ion-interaction parameters for neodymium with tetraborate and SIT interaction coefficients were also determined and reported.

  12. Co-norming the WAIS-III and WMS-III: Is there a test-order effect on IQ and memory scores?

    PubMed

    Zhu, J; Tulsky, D S

    2000-11-01

    Test-order effect on the WAIS-III and WMS-III scores was evaluated using the WMS-III standardization sample. Participants completed the standardization editions of the WAIS-III and WMS-III in one session, with the tests administered in roughly counterbalanced order. Repeated measure MANOVA analyses were conducted to determine if there was an overall test-order effect for subtest, index, or IQ scores. No significant test-order effects were found for either the WAIS-III index or IQ scores or for the WMS-III index scores. At the subtest level, the majority of the WAIS-III and WMS-III subtests did not show a significant test-order effect. The exceptions were Digit Span and Digit Symbol-Coding on the WAIS-III and Faces II and Logical Memory II on the WMS-III. Although statistically significant test-order effects were found on these subtests, the effect sizes were small. This study indicates that the test-order effect is not a potential threat to the internal validity of the WAIS-III and WMS-III normative data. The practical implications of the current study are discussed.

  13. Heterogeneously integrated III-V/Si single mode lasers based on a MMI-ring configuration and triplet-ring reflectors

    NASA Astrophysics Data System (ADS)

    Keyvaninia, S.; Verstuyft, S.; Lelarge, F.; Duan, G.-H.; Messaoudene, S.; Fédéli, J. M.; Geluk, E. J.; De Vries, T.; Smalbrugge, B.; Bolk, J.; Smit, M.; Van Thourhout, D.; Roelkens, G.

    2013-05-01

    In this paper we show that using a DVS-BCB adhesive bonding process compact heterogeneously integrated III-V/silicon single mode lasers can be realized. Two new designs were implemented: in a first design a multimode interferometer coupler (MMI) - ring resonator combination is used to provide a comb-like reflection spectrum, while in a second design a triplet-ring reflector design is used to obtain the same. A broadband silicon Bragg grating reflector is implemented on the other side of the cavity. The III-V optical amplifier is heterogeneously integrated on the 400nm thick silicon waveguide layer, which is compatible with high-performance modulator designs and allows for efficient coupling to a standard 220nm high index contrast silicon waveguide layer. In order to make the optical coupling efficient, both the III-V waveguide and the silicon waveguide are tapered, with a tip width of the III-V waveguide of around 500nm. The III-V thin film optical amplifier is implemented as a 3μm wide mesa etched through to the n-type InP contact layer. In this particular device implementation the amplifier section was 500μm long. mW-level waveguide coupled output power at 20°C and a side mode suppression ratio of more than 40dB is obtained.

  14. Letter report seismic shutdown system failure mode and effect analysis

    SciTech Connect

    KECK, R.D.

    1999-09-01

    The Supply Ventilation System Seismic Shutdown ensures that the 234-52 building supply fans, the dry air process fans and vertical development calciner are shutdown following a seismic event. This evaluates the failure modes and determines the effects of the failure modes.

  15. Geometric Effects on the Amplification of First Mode Instability Waves

    NASA Technical Reports Server (NTRS)

    Kirk, Lindsay C.; Candler, Graham V.

    2013-01-01

    The effects of geometric changes on the amplification of first mode instability waves in an external supersonic boundary layer were investigated using numerical techniques. Boundary layer stability was analyzed at Mach 6 conditions similar to freestream conditions obtained in quiet ground test facilities so that results obtained in this study may be applied to future test article design to measure first mode instability waves. The DAKOTA optimization software package was used to optimize an axisymmetric geometry to maximize the amplification of the waves at first mode frequencies as computed by the 2D STABL hypersonic boundary layer stability analysis tool. First, geometric parameters such as nose radius, cone half angle, vehicle length, and surface curvature were examined separately to determine the individual effects on the first mode amplification. Finally, all geometric parameters were allowed to vary to produce a shape optimized to maximize the amplification of first mode instability waves while minimizing the amplification of second mode instability waves. Since first mode waves are known to be most unstable in the form of oblique wave, the geometries were optimized using a broad range of wave frequencies as well as a wide range of oblique wave angles to determine the geometry that most amplifies the first mode waves. Since first mode waves are seen most often in flows with low Mach numbers at the edge of the boundary layer, the edge Mach number for each geometry was recorded to determine any relationship between edge Mach number and the stability of first mode waves. Results indicate that an axisymmetric cone with a sharp nose and a slight flare at the aft end under the Mach 6 freestream conditions used here will lower the Mach number at the edge of the boundary layer to less than 4, and the corresponding stability analysis showed maximum first mode N factors of 3.

  16. Mode-splitting of a non-polarizing guided mode resonance filter by substrate overetching effect

    NASA Astrophysics Data System (ADS)

    Saleem, Muhammad Rizwan; Honkanen, Seppo; Turunen, Jari

    2014-03-01

    We investigate substrate overetch effect on resonance properties of sub-wavelength titanium oxide (TiO2) Guided Mode Resonance Filters (TiO2-GMRFs). The TiO2-GMRF is designed and fabricated to possess a non-polarizing behavior, which is strongly dependent on substrate (fused silica) overetch depth. For non-polarizing gratings at resonance, TE- and TM-modes have the same propagation constants. However, an overetch substrate effect results in splitting of the degenerate modes, which is studied theoretically and experimentally. The TiO2-SiO2 GMRFs are designed by Fourier Modal method (FMM) based on the rigorous calculation of electromagnetic diffraction theory at a designed wavelength of 850 nm. The TiO2-SiO2 gratings are fabricated by Atomic Layer Deposition (ALD), Electron Beam Lithography (EBL), and Reactive Ion Etching (RIE), and they are subsequently characterized structurally by Scanning Electron Microscopy (SEM) and optically by a spectroscopic ellipsometer. Several grating samples are fabricated by gradually increasing the overetch depth into fused silica and measuring the extent of TE- and TM-mode-splitting. A close agreement between the calculated and experimentally measured resonance wavelength spectral shift is found to describe the mode splitting of non-polarizing gratings.

  17. Geometric Effects on the Amplification of First Mode Instability Waves

    NASA Astrophysics Data System (ADS)

    Kirk, Lindsay Christine

    The effects of geometric changes on the amplification of first mode instability waves in an external supersonic boundary layer were investigated using numerical techniques. Boundary layer stability was analyzed at Mach 6 conditions similar to freestream conditions obtained in quiet ground test facilities so that results obtained in this study may be applied to future test article design to measure first mode instability waves. First, geometric parameters such as nose radius, cone half angle, vehicle length, and surface curvature for an axisymmetric cone geometry were examined separately to determine the individual effects on the first mode amplification. The DAKOTA optimization software package was then used to optimize the geometry to maximize the amplification of waves at first mode frequencies and to minimize the amplification of the waves at second mode frequencies, as computed by the 2D STABL hypersonic boundary layer stability analysis tool. This was accomplished by allowing all geometric parameters in the sensitivity study to vary to produce a shape optimized to maximize the amplification of first mode instability waves while minimizing the amplification of second mode instability waves. During this process, boundary layer edge properties were recorded to investigate any correlations. Results of the sensitivity analysis indicate that an axisymmetric cone with a sharp nose or an axisymmetric cone with a high degree of concave curvature under the Mach 6 freestream conditions used here will cause the largest amplification of first mode instability waves.

  18. Failure Modes and Effects Analysis (FMEA) Assistant Tool Feasibility Study

    NASA Technical Reports Server (NTRS)

    Flores, Melissa; Malin, Jane T.

    2013-01-01

    An effort to determine the feasibility of a software tool to assist in Failure Modes and Effects Analysis (FMEA) has been completed. This new and unique approach to FMEA uses model based systems engineering concepts to recommend failure modes, causes, and effects to the user after they have made several selections from pick lists about a component s functions and inputs/outputs. Recommendations are made based on a library using common failure modes identified over the course of several major human spaceflight programs. However, the tool could be adapted for use in a wide range of applications from NASA to the energy industry.

  19. Kinetic effect of toroidal rotation on the geodesic acoustic mode

    SciTech Connect

    Guo, W. Ye, L.; Zhou, D.; Xiao, X.; Wang, S.

    2015-01-15

    Kinetic effects of the toroidal rotation on the geodesic acoustic mode are theoretically investigated. It is found that when the toroidal rotation increases, the damping rate increases in the weak rotation regime due to the rotation enhancement of wave-particle interaction, and it decreases in the strong rotation regime due to the reduction of the number of resonant particles. Theoretical results are consistent with the behaviors of the geodesic acoustic mode recently observed in DIII-D and ASDEX-Upgrade. The kinetic damping effect of the rotation on the geodesic acoustic mode may shed light on the regulation of turbulence through the controlling the toroidal rotation.

  20. Possible confirmation of the existence of the ergoregion by the Kerr quasinormal mode in gravitational waves from a Population III massive black hole binary

    NASA Astrophysics Data System (ADS)

    Kinugawa, Tomoya; Nakano, Hiroyuki; Nakamura, Takashi

    2016-03-01

    The existence of the ergoregion of the Kerr space-time has not yet been confirmed observationally. We show that the confirmation would be possible by observing the quasinormal mode in gravitational waves. As an example, using the recent population synthesis results of Population III (Pop III) binary black holes, we find that the peak of the final merger mass (M_f) is about 50 M_{⊙}, while the fraction of the final spin q_f = a_f/M_f > 0.7 needed for the confirmation of a part of the ergoregion is {˜ }77%. To confirm the frequency of the quasinormal mode, SNR > 35 is needed. The standard model of Pop III population synthesis tells us that the event rate for the confirmation of more than 50% of the ergoregion by second generation gravitational wave detectors is {˜ }2.3 events yr^{-1 (SFR_p/(10^{-2.5} M_⊙ yr^{-1} Mpc^{-3}))} \\cdot ([f_b/(1+f_b)]/0.33), where SFR_p and f_b are the peak value of the Pop III star formation rate and the fraction of binaries, respectively.

  1. Arc fusion splicing effects in large-mode-area single-mode ytterbium-doped fibers.

    PubMed

    Feng, Ting; Jenkins, Micah H; Yan, Fengping; Gaylord, Thomas K

    2013-11-10

    For the first time the effects of arc fusion splicing on the residual stress and refractive index of large-mode-area single-mode ytterbium-doped fibers (YDFs) are investigated using a state-of-the-art three-dimensional concurrent stress-index measurement method. The results, based on a commercially available fiber, describe a host of perturbations that decrease the core/cladding refractive index difference by as much as 1.74 × 10(-3) over an axial length of many hundreds of wavelengths. Simulations indicate that these perturbations result in an expansion of the mode-field-diameter by 39.6% and, based on the measured sample, result in an extra splice loss of 20.8%. The results of this investigation will be useful in the design and optimization of high-power all-fiber YDF lasers and amplifiers. PMID:24216728

  2. Arc fusion splicing effects in large-mode-area single-mode ytterbium-doped fibers.

    PubMed

    Feng, Ting; Jenkins, Micah H; Yan, Fengping; Gaylord, Thomas K

    2013-11-10

    For the first time the effects of arc fusion splicing on the residual stress and refractive index of large-mode-area single-mode ytterbium-doped fibers (YDFs) are investigated using a state-of-the-art three-dimensional concurrent stress-index measurement method. The results, based on a commercially available fiber, describe a host of perturbations that decrease the core/cladding refractive index difference by as much as 1.74 × 10(-3) over an axial length of many hundreds of wavelengths. Simulations indicate that these perturbations result in an expansion of the mode-field-diameter by 39.6% and, based on the measured sample, result in an extra splice loss of 20.8%. The results of this investigation will be useful in the design and optimization of high-power all-fiber YDF lasers and amplifiers.

  3. Neoclassical viscosity effects on resistive magnetohydrodynamic modes in toroidal geometry

    SciTech Connect

    Yang, J.G.; Oh, Y.H.; Choi, D.I. ); Kim, J.Y.; Horton, W. )

    1992-03-01

    The flux-surface-averaged linearized resistive magnetohydrodynamic (MHD) boundary-layer equations including the compressibility, diamagnetic drift, and neoclassical viscosity terms are derived in toroidal geometry. These equations describe the resistive layer dynamics of resistive MHD modes over the collisionality regime between the banana plateau and the Pfirsch--Schlueter. From the resulting equations, the effects of neoclassical viscosity on the stability of the tearing and resistive ballooning modes are investigated numerically. Also, a study is given for the problem of how the neoclassical resistive MHD mode is generated as the collisionality is reduced. It is shown that the neoclassical viscosity terms give a significant destabilizing effect for the tearing and resistive ballooning modes. This destabilization comes mainly from the reduction of the stabilizing effect of the parallel ion sound compression by the ion neoclassical viscosity. In the banana-plateau collisionality limit, where the compressibility is negligible, the dispersion relations of the tearing and resistive ballooning modes reduce to the same form, with the threshold value of the driving force given by {Delta}{sub {ital c}}=0. On the other hand, with the finite neoclassical effect it is found that the neoclassical resistive MHD instability is generated in agreement with previous results. Furthermore, it is shown that this later instability can be generated in a wide range of the collisionality including near the Pfirsch--Schlueter regime as well as the banana-plateau regime, suggesting that this mode is a probable cause of anomalous transport.

  4. Effects of voids on delamination behavior under static and fatigue mode I and mode II

    NASA Astrophysics Data System (ADS)

    Abdelal, Nisrin Rizek

    Composite materials have become materials of choice for wind turbine blade manufacturing due to their high specific stiffness, strength and fatigue life. Glass fiber composites are used extensively in light-weight structural components for wind turbines, aircrafts, marine craft and high performance automobile because glass fiber is inexpensive and usually provides high strength to weight ratio and good in-plane mechanical properties. The high cycle fatigue resistance of composite materials used in wind turbine blades has been recognized as a major uncertainty in predicting the reliability of wind turbines over their design lifetime. Blades are expected to experience 108 to 109 fatigue cycles over a 20 to 30 year lifetime. Delamination or interlaminar failure is a serious failure mode observed in composite structures. Even partial delamination will lead to a loss of local stiffness, which can preclude buckling failure. Manufacturing process defects such as voids and fiber waviness degrade the fatigue life and delamination resistance of the blade's composite. This research describes the effect of voids on static and fatigue interlaminar fracture behavior under mode I and mode II loading of wind turbine glass fiber composites. Samples with different void volume fractions in the 0.5%-7% range were successfully obtained by varying the vacuum in the hand layup vacuum bagging manufacturing process. Void content was characterized using four different methods; ultrasonic scanning, epoxy burn off, serial sectioning and X-Ray computed tomography. The effect of voids on both mode I and mode II interlaminar fracture toughness under static and fatigue loading was investigated. Finally, fractographic analysis (using optical and scanning electron microscopy) was conducted. The results showed that voids leads to slight reduction in static modes I and II interlaminar fracture toughness. In addition, voids lead to a decrease in modes I and II maximum cyclic strain energy release

  5. Survey mode effects on valuation of environmental goods.

    PubMed

    Bell, Jason; Huber, Joel; Viscusi, W Kip

    2011-04-01

    This article evaluates the effect of the choice of survey recruitment mode on the value of water quality in lakes, rivers, and streams. Four different modes are compared: bringing respondents to one central location after phone recruitment, mall intercepts in two states, national phone-mail survey, and an Internet survey with a national, probability-based panel. The modes differ in terms of the representativeness of the samples, non-response rates, sample selection effects, and consistency of responses. The article also shows that the estimated value of water quality can differ substantially depending on the survey mode. The national Internet panel has the most desirable properties with respect to performance on the four important survey dimensions of interest. PMID:21695037

  6. Trapped electron effects on ηi-mode and trapped electron mode in RFP plasmas

    NASA Astrophysics Data System (ADS)

    Liu, S. F.; Guo, S. C.; Kong, W.; Dong, J. Q.

    2014-04-01

    The drift instabilities in the toroidal reversed field pinch (RFP) plasmas are numerically studied with gyrokinetic integral eigenmode equations, by taking into account the trapped electrons (TEs) and full ion kinetic effects. Both the collisionless and collisional plasmas are investigated. Two topics are addressed: the TE effects on the ion temperature gradient driven mode, and the instability of the trapped electron mode (TEM). A comparison with a circular tokamak configuration has been made. Although the TEs generally play a similar role in RFPs as they do in tokamaks, their effects become significant in RFPs only when very steep density/temperature profiles exist. Indeed, the instability of the TEM in RFP plasmas requires a much steeper density/temperature gradient and has a much narrower kθρs spectrum than in tokamak plasmas.

  7. Langmuir Mixing Effects on Global Climate: WAVEWATCH III in CESM

    NASA Astrophysics Data System (ADS)

    Li, Qing; Webb, Adrean; Fox-Kemper, Baylor; Craig, Anthony; Danabasoglu, Gokhan; Large, William; Vertenstein, Mariana

    2015-11-01

    Large Eddy Simulations (LES) have shown the effects of ocean surface gravity waves in enhancing the ocean boundary layer mixing through Langmuir turbulence. Neglecting this Langmuir mixing process may contribute to the common shallow bias in mixed layer depth in regions of the Southern Ocean and the Northern Atlantic in most state-of-the-art climate models. A third generation wave model, WAVEWATCH III, has been incorporated as a component of the Community Earth System Model, version 1.2 (CESM1.2). In particular, the wave model is now coupled with the ocean model through a modified version of the K-Profile Parameterization (KPP) to approximate the influence of Langmuir mixing. Unlike past studies, the wind-wave misalignment and the effects of Stokes drift penetration depth are considered through empirical scalings based on the rate of mixing in LES. Wave-Ocean only experiments show substantial improvements in the shallow biases of mixed layer depth in the Southern Ocean. Ventilation is enhanced and low concentration biases of pCFC-11 are reduced in the Southern Hemisphere. A majority of the improvements persist in the presence of other climate feedbacks in the fully coupled experiments.

  8. Langmuir Mixing Effects on Global Climate: Wavewatch III in CESM

    NASA Astrophysics Data System (ADS)

    Li, Q.; Fox-Kemper, B.; Webb, A.; Arbetter, T. E.

    2014-12-01

    Large-Eddy Simulations (LES) have shown the effects of surface wind waves in enhancing ocean boundary layer mixing, yet this Langmuir mixing process is missing in almost all the state-of-the-art climate models and may contribute to the shallow biases of mixed layer depth in the Southern Ocean and the Northern Atlantic in most climate models. In this study a third generation wave model, WAVEWATCH III, has been incorporated as a component of the Community Earth System Model, version 1.2 (CESM1.2). In particular, the wave model is now coupled with the ocean model through a modified version of the K-Profile Parameterization (KPP) including the influence of Langmuir mixing. The misalignment of wind and waves and the effects of Stokes depth are considered in our implementation of Langmuir mixing in KPP. Wave-ocean only tests show substantial improvements in the upper ocean simulation, including reductions in both the shallow biases of mixed layer depth and the low biases of pCFC-11 in the Southern Ocean. Ocean-Ice-Wave and Atmosphere-Ocean-Ice-Wave coupled tests confirm these improvements when other climate feedbacks are included. Progress toward a more computationally efficient data wave model will be summarized.

  9. Langmuir mixing effects on global climate: WAVEWATCH III in CESM

    NASA Astrophysics Data System (ADS)

    Li, Qing; Webb, Adrean; Fox-Kemper, Baylor; Craig, Anthony; Danabasoglu, Gokhan; Large, William G.; Vertenstein, Mariana

    2016-07-01

    Large-Eddy Simulations (LES) have shown the effects of ocean surface gravity waves in enhancing the ocean boundary layer mixing through Langmuir turbulence. Neglecting this Langmuir mixing process may contribute to the common shallow bias in mixed layer depth in regions of the Southern Ocean and the Northern Atlantic in most state-of-the-art climate models. In this study, a third generation wave model, WAVEWATCH III, has been incorporated as a component of the Community Earth System Model, version 1.2 (CESM1.2). In particular, the wave model is now coupled with the ocean model through a modified version of the K-Profile Parameterization (KPP) to approximate the influence of Langmuir mixing. Unlike past studies, the wind-wave misalignment and the effects of Stokes drift penetration depth are considered through empirical scalings based on the rate of mixing in LES. Wave-Ocean only experiments show substantial improvements in the shallow biases of mixed layer depth in the Southern Ocean. Ventilation is enhanced and low concentration biases of pCFC-11 are reduced in the Southern Hemisphere. A majority of the improvements persist in the presence of other climate feedbacks in the fully coupled experiments. In addition, warming of the subsurface water over the majority of global ocean is observed in the fully coupled experiments with waves, and the cold subsurface ocean temperature biases are reduced.

  10. Protective effects of antithrombin III supplementation on warm ischemia and reperfusion injury in rat liver.

    PubMed

    Okano, K; Kokudo, Y; Okajima, K; Hossain, M A; Ishimura, K; Yachida, S; Tsubouchi, T; Wakabayashi, H; Maeba, T; Maeta, H

    1996-10-01

    The effect of antithrombin III (AT III) supplementation on energy status, microcirculation, cytoprotection, and prostacyclin (PGI2) production during and after a period of warm ischemia of the rat liver was investigated. AT III supplementation (250 units/kg) stimulate prostaglandin I2 (PGI2) production from 1 hour after administration, with maximal production observed at 3 hours. Ischemia was induced by occluding the hepatoduodenal ligament for 30 minutes, and experiments were continued for 60 minutes after reperfusion. The rats received AT III (250 units/kg IC) 30 minutes before induction of liver ischemia (AT III group). In the AT III group, recovery of the beta-ATP/inorganic phosphate ratio measured by 31P nuclear magnetic resonance showed significant improvement (p < 0.01), and the recovery of tissue blood flow markedly improved (p < 0.01) compared to the saline-treated group (control group). Leakages of aspartame aminotransferase, alanine aminotransferase, and lactate dehydrogenase were mitigated in the AT III group (p < 0. 05). Ultrastructural alterations of sinusoidal endothelial cells were markedly reduced in the AT III group. The PGI2 level at the end of reperfusion was significantly elevated (p < 0.01) in the AT III group compared to the control group. The results of this study indicated that pretreatment with AT III significantly improved the energy status and microcirculation, as well as histologic damage, after liver ischemia and reperfusion. One of the fundamental effects of AT III might be mediated through the production of prostacyclin.

  11. Effect of Population III multiplicity on dark star formation

    NASA Astrophysics Data System (ADS)

    Stacy, Athena; Pawlik, Andreas H.; Bromm, Volker; Loeb, Abraham

    2012-03-01

    We numerically study the mutual interaction between dark matter (DM) and Population III (Pop III) stellar systems in order to explore the possibility of Pop III dark stars within this physical scenario. We perform a cosmological simulation, initialized at z˜ 100, which follows the evolution of gas and DM. We analyse the formation of the first minihalo at z˜ 20 and the subsequent collapse of the gas to densities of 1012 cm-3. We then use this simulation to initialize a set of smaller scale 'cut-out' simulations in which we further refine the DM to have spatial resolution similar to that of the gas. We test multiple DM density profiles, and we employ the sink particle method to represent the accreting star-forming region. We find that, for a range of DM configurations, the motion of the Pop III star-disc system serves to separate the positions of the protostars with respect to the DM density peak, such that there is insufficient DM to influence the formation and evolution of the protostars for more than ˜5000 years. In addition, the star-disc system causes gravitational scattering of the central DM to lower densities, further decreasing the influence of DM over time. Any DM-powered phase of Pop III stars will thus be very short-lived for the typical multiple system, and DM will not serve to significantly prolong the life of Pop III stars.

  12. Effect of Population III Multiplicity on Dark Star Formation

    NASA Technical Reports Server (NTRS)

    Stacy, Athena; Pawlik, Andreas H.; Bromm, Volker; Loeb, Abraham

    2012-01-01

    We numerically study the mutual interaction between dark matter (DM) and Population III (Pop III) stellar systems in order to explore the possibility of Pop III dark stars within this physical scenario. We perform a cosmological simulation, initialized at z approx. 100, which follows the evolution of gas and DM. We analyze the formation of the first mini halo at z approx. 20 and the subsequent collapse of the gas to densities of 10(exp 12)/cu cm. We then use this simulation to initialize a set of smaller-scale 'cut-out' simulations in which we further refine the DM to have spatial resolution similar to that of the gas. We test multiple DM density profiles, and we employ the sink particle method to represent the accreting star-forming region. We find that, for a range of DM configurations, the motion of the Pop III star-disk system serves to separate the positions of the protostars with respect to the DM density peak, such that there is insufficient DM to influence the formation and evolution of the protostars for more than approx. 5000 years. In addition, the star-disk system causes gravitational scattering of the central DM to lower densities, further decreasing the influence of DM over time. Any DM-powered phase of Pop III stars will thus be very short-lived for the typical multiple system, and DM will not serve to significantly prolong the life of Pop III stars.

  13. Identification of nonlinear boundary effects using nonlinear normal modes

    NASA Astrophysics Data System (ADS)

    Ahmadian, Hamid; Zamani, Arash

    2009-08-01

    Local nonlinear effects due to micro-slip/slap introduced in boundaries of structures have dominant influence on their lower modal model. This paper studies these effects by experimentally observing the behavior of a clamped-free beam structure with local nonlinearities due to micro-slip at the clamped end. The structure is excited near one of its resonance frequencies and recorded responses are employed to identify the nonlinear effects at the boundary. The nonlinear response of structure is defined using an amplitude-dependent nonlinear normal mode identified from measured responses. A new method for reconstructing nonlinear normal mode is represented in this paper by relating the nonlinear normal mode to the clamped end displacement-dependent stiffness parameters using an eigensensitivity analysis. Solution of obtained equations results equivalent stiffness models at different vibration amplitudes and the corresponding nonlinear normal mode is identified. The approach results nonlinear modes with efficient capabilities in predicting dynamical behavior of the structure at different loading conditions. To evaluate the efficiency of the identified model, the structure is excited at higher excitation load levels than those employed in identification procedures and the observed responses are compared with the predictions of the model at the corresponding input force levels. The predictions are in good agreement with the observed behavior indicating success of identification procedure in capturing the physical merits involve in the boundary local nonlinearities.

  14. Linguistic-Numeric Presentation Mode Effects on Risky Option Preferences

    PubMed

    Dusenbury; Fennema

    1996-11-01

    In this study, we examine preferences between lotteries with chances presented either numerically or linguistically. Presentation mode is predicted to affect preferences due to the perception of linguistic chance as skewed distributions of risk. Based upon weighting functions incorporating risk/uncertainty aversion from ambiguity theory and cumulative prospect theory, we predict that presentation mode effects on risky choices will be detectable in very small risks and in large risks. In two experiments, subjects chose between both gain and loss lotteries with constant payoffs and equivalent numeric and linguistic chances. Presentation mode affected choices when chances were above 50%, where lotteries with numeric chances were more frequently preferred in gains while lotteries with linguistic chances were more often preferred in losses. The effect of presentation mode for low-chance lotteries (5% and less) also affected choices such that numeric choices were generally preferred more frequently in losses and linguistically expressed choices were generally preferred more often in gains. Overall, these results suggest that theories of the effects of second order uncertainty on risky choice may be used to model decisions involving linguistic risk. They also suggest that the study of the perception of linguistic risk assessments can provide insight into the cognitive processing behind the weighting functions proposed to depict decision under risk and uncertainty. Finally, the results have practical implications since information providers can affect decision makers' choices by controlling presentation mode in such a way as to alter the relative attractiveness of uncertain events.

  15. Effect of plasma motion on tearing modes in cylindrical plasmas

    NASA Astrophysics Data System (ADS)

    Xu, J. Q.; Peng, X. D.

    2015-10-01

    The effect of equilibrium plasma motion on the resistive m/n = 2/1 tearing mode (TM) in low β plasmas is investigated in cylindrical geometry (with m and n being poloidal and toroidal mode numbers). Without equilibrium plasma motion but with viscosity, the TM stability is mainly determined by the Reynolds number S and reaches maximum near S = 104, which is consistent with previous findings. The poloidal plasma rotation has stabilizing effect on TM; however, the rotation shear has destabilization effect in the low viscosity regime. The axial plasma motion has strong stabilizing effect on TM in the low viscosity regime for Prandtl number Pr < 1, while its shear has slight stabilizing effect with the decrease of growth rate less than 15%. When the axial velocity becomes large enough, the mode frequency tends to be independent of the Prandtl number. In the presence of parallel plasma motion, the growth rate is determined by the axial component at low parallel velocity, while determined by poloidal component at large parallel velocity. The parallel plasma motion drives the TM rotating in the opposite direction. It is shown that the equilibrium motion reduces the growth rate of TM by changing the phase difference and coupling coefficient between potential perturbation and magnetic flux perturbation (deviating from π/2 ), which results in a lower mode frequency. Compared to the role of velocity shear, the magnitude of plasma velocity itself at the m/n = 2/1 rational surface is dominant in determining the TM characteristics.

  16. Nonlinear simulations of particle source effects on edge localized mode

    SciTech Connect

    Huang, J.; Tang, C. J.; Chen, S. Y.; Wang, Z. H.

    2015-12-15

    The effects of particle source (PS) with different intensities and located positions on Edge Localized Mode (ELM) are systematically studied with BOUT++ code. The results show the ELM size strongly decreases with increasing the PS intensity once the PS is located in the middle or bottom of the pedestal. The effects of PS on ELM depend on the located position of PS. When it is located at the top of the pedestal, peeling-ballooning (P-B) modes can extract more free energy from the pressure gradient and grow up to be a large filament at the initial crash phase and the broadening of mode spectrum can be suppressed by PS, which leads to more energy loss. When it is located in the middle or bottom of the pedestal, the extraction of free energy by P-B modes can be suppressed, and a small filament is generated. During the turbulence transport phase, the broader mode spectrum suppresses the turbulence transport when PS is located in the middle, while the zonal flow plays an important role in damping the turbulence transport when PS is located at the bottom.

  17. The effect of search mode on dimension weighting

    PubMed Central

    Kumada, Takatsune

    2014-01-01

    In a visual feature search task, reaction times to a singleton target are known to be shorter when participants have advance knowledge of the defining-features of targets. The present study examined whether the prior-knowledge effect is influenced by search modes (feature vs. singleton). In addition, using a variant of the flanker task, the present study assessed whether prior-knowledge affected efficiency of attentional focusing to a target. When participants performed a target discrimination task (i.e., compound search task), using a singleton detection mode, no prior-knowledge effect was found (Experiments 1 and 3). However, when the same task was performed using a feature search mode, prior-knowledge facilitated performance (Experiment 2). This suggests that the dimension weighting of a target-defining feature is modulated by the search mode. Also flanker response congruency was affected by prior-knowledge suggesting that the dimension weighting correlated with attentional focusing to targets. On the other hand, inter-trial dimensional priming was not affected by the search mode. Implications for mechanisms of feature-based top-down control of attention in visual feature search are discussed. PMID:25339919

  18. Effect of praseodymium(III) on zinc(II) species in human interstitial fluid.

    PubMed

    Zhang, Haiyuan; Wang, Jinping; Lu, Xin; Yang, Kuiyue; Niu, Chunji

    2005-11-01

    A multiphase model of metal ion species in human interstitial fluid was constructed under physiological conditions. The effect of Pr(III) on Zn(II) species was studied. At the normal conditions, Zn(II) species mainly distribute in [Zn(HSA)], [Zn(IgG)], and [Zn(Cys)(2)H](+). With the Pr(III) level increased, the apparent competition of Pr(III) for ligands lead to the redistribution of Zn(II) species.

  19. Acoustic attenuation, phase and group velocities in liquid-filled pipes III: nonaxisymmetric propagation and circumferential modes in lossless conditions.

    PubMed

    Baik, Kyungmin; Jiang, Jian; Leighton, Timothy G

    2013-03-01

    Equations for the nonaxisymmetric modes that are axially and circumferentially propagating in a liquid-filled tube with elastic walls surrounded by air/vacuum are presented using exact elasticity theory. Dispersion curves for the axially propagating modes are obtained and verified through comparison with measurements. The resulting theory is applied to the circumferential modes, and the pressures and the stresses in the liquid-filled pipe are calculated under external forced oscillation by an acoustic source. This provides the theoretical foundation for the narrow band acoustic bubble detector that was subsequently deployed at the Target Test Facility (TTF) of the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL), TN.

  20. Enhancing Effective Chemistry Learning through Hypermedia Instructional Mode of Delivery

    ERIC Educational Resources Information Center

    Abanikannda, Mutahir Oluwafemi

    2016-01-01

    This study provides a framework for the production of Hypermedia Instructional package. It also assessed the effectiveness of hypermedia instructional mode of delivery on students? performance in Chemistry. This is with a view of improving the learning of Chemistry which may eventually help to improve students? performance. The developmental study…

  1. Short-Term Memory Effects in Four Learning Modes.

    ERIC Educational Resources Information Center

    Furukawa, James M.; And Others

    The effect of three levels of short-term memory (STM) and four learning modes (control, chunking organizational strategy, programmed instruction, and adjunct questions) on prose learning and recall was studied. The participants in this study were educational psychology students at Towson State College in Maryland. Significant STM and learning mode…

  2. Insights into the coordination mode of quercetin with the Al(III) ion from a combined experimental and theoretical study.

    PubMed

    Furia, Emilia; Marino, Tiziana; Russo, Nino

    2014-05-21

    Combining potentiometric, spectroscopic and theoretical DFT computations we have studied the formation of the Al(iii)-quercetin complex in ethanol solution. The possible complexation sites have been considered on the basis of all the experimental and theoretical tools used. Results supported proposing a 1 : 1 neutral complex and the possibility to have different isomers in solution.

  3. Failure Modes and Effects Analysis (FMEA): A Bibliography

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Failure modes and effects analysis (FMEA) is a bottom-up analytical process that identifies process hazards, which helps managers understand vulnerabilities of systems, as well as assess and mitigate risk. It is one of several engineering tools and techniques available to program and project managers aimed at increasing the likelihood of safe and successful NASA programs and missions. This bibliography references 465 documents in the NASA STI Database that contain the major concepts, failure modes or failure analysis, in either the basic index of the major subject terms.

  4. Stabilization effect of Weibel modes in relativistic laser fusion plasma

    NASA Astrophysics Data System (ADS)

    Belghit, Slimen; Sid, Abdelaziz

    2016-06-01

    In this work, the Weibel instability (WI) due to inverse bremsstrahlung (IB) absorption in a laser fusion plasma has been investigated. The stabilization effect due to the coupling of the self-generated magnetic field by WI with the laser wave field is explicitly shown. In this study, the relativistic effects are taken into account. Here, the basic equation is the relativistic Fokker-Planck (F-P) equation. The main obtained result is that the coupling of self-generated magnetic field with the laser wave causes a stabilizing effect of excited Weibel modes. We found a decrease in the spectral range of Weibel unstable modes. This decreasing is accompanied by a reduction of two orders in the growth rate of instable Weibel modes or even stabilization of these modes. It has been shown that the previous analysis of the Weibel instability due to IB has overestimated the values of the generated magnetic fields. Therefore, the generation of magnetic fields by the WI due to IB should not affect the experiences of an inertial confinement fusion.

  5. Isotopic effects on the phonon modes in boron carbide.

    PubMed

    Werheit, H; Kuhlmann, U; Rotter, H W; Shalamberidze, S O

    2010-10-01

    The effect of isotopes ((10)B-(11)B; (12)C-(13)C) on the infrared- and Raman-active phonons of boron carbide has been investigated. For B isotopes, the contributions of the virtual crystal approximation, polarization vector and isotopical disorder are separated. Boron and carbon isotope effects are largely opposite to one another and indicate the share of the particular atoms in the atomic assemblies vibrating in specific phonon modes. Some infrared-active phonons behave as expected for monatomic boron crystals.

  6. The effect of mixed mode precracking on the mode 1 fracture toughness of composite laminates

    NASA Technical Reports Server (NTRS)

    Shankar, Prashanth; Bascom, Williard D.; Nairn, John A.

    1993-01-01

    We subjected double cantilever beam specimens from four different composite materials to mixed-mode precracking. Three different precracking mode 1 to mode 2 ratios were used--1 to 4, 1 to 1, and 4 to 1. Following precracking the specimens were tested for mode I fracture toughness. The mixed-mode precracking often influenced the mode 1 toughness and its influence persisted for as much as 60 mm of mode 1 crack growth. We tested composites with untoughened matrices, composites with rubber-toughened matrices, and composites with interlayer toughening. Depending on material type and precracking mode ratio, the precracking could cause either a significant increase or a significant decrease in the mode 1 fracture toughness.

  7. The Effects of Non-Normality on Type III Error for Comparing Independent Means

    ERIC Educational Resources Information Center

    Mendes, Mehmet

    2007-01-01

    The major objective of this study was to investigate the effects of non-normality on Type III error rates for ANOVA F its three commonly recommended parametric counterparts namely Welch, Brown-Forsythe, and Alexander-Govern test. Therefore these tests were compared in terms of Type III error rates across the variety of population distributions,…

  8. Asymmetric large-mode-area photonic crystal fiber structure with effective single-mode operation: design and analysis.

    PubMed

    Saini, Than Singh; Kumar, Ajeet; Sinha, Ravindra Kumar

    2016-03-20

    The asymmetrical structure of photonic crystal fiber has been reported for a large mode area with the single-mode operation. The design works on the principle of bend-induced mode filtering. The proposed structure can be designed (i) by introducing down-doped material rods in place of nine air holes of the inner ring near the core of the structure and (ii) by increasing the diameter of the rest of the three air holes of the same ring in the direction of bending. These three air holes together with nine down-doped material rods control the mode field inside the core region and hence the bending losses of the modes. The single-mode operation is ensured by introducing high bend loss for the first higher order mode and very low bend loss for the fundamental mode. The finite-element-method-based anisotropic perfectly matched layer boundary condition has been applied for accurate analysis of bend loss of the structure. Numerical results show that effective single-mode operation can be ensured with a mode area as large as 1530  μm2 at bend state with a bend radius of 30 cm. The proposed photonic crystal optical fiber with such a large mode area can have potential applications in compact high-power delivery devices such as high-power fiber lasers and amplifiers. PMID:27140567

  9. 25 CFR 291.13 - When do Class III gaming procedures for an Indian tribe become effective?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false When do Class III gaming procedures for an Indian tribe... ECONOMIC ENTERPRISES CLASS III GAMING PROCEDURES § 291.13 When do Class III gaming procedures for an Indian tribe become effective? Upon approval of Class III gaming procedures for the Indian tribe under...

  10. 25 CFR 291.13 - When do Class III gaming procedures for an Indian tribe become effective?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false When do Class III gaming procedures for an Indian tribe... ECONOMIC ENTERPRISES CLASS III GAMING PROCEDURES § 291.13 When do Class III gaming procedures for an Indian tribe become effective? Upon approval of Class III gaming procedures for the Indian tribe under...

  11. Mode splitting effect in FEMs with oversized Bragg resonators

    NASA Astrophysics Data System (ADS)

    Peskov, N. Yu.; Kaminsky, A. K.; Kuzikov, S. V.; Perelstein, E. A.; Sedykh, S. N.; Sergeev, A. S.

    2016-07-01

    Splitting of the fundamental mode in an oversized Bragg resonator with a step of the corrugation phase, which operates over the feedback loop involving the waveguide waves of different transverse structures, was found to be the result of mutual influence of the neighboring zones of the Bragg scattering. Theoretical description of this effect was developed within the framework of the advanced (four-wave) coupled-wave approach. It is shown that mode splitting reduces the selective properties, restricts the output power, and decreases the stability of the narrow-band operating regime in the free-electron maser (FEM) oscillators based on such resonators. The results of the theoretical analysis were confirmed by 3D simulations and "cold" microwave tests. Experimental data on Bragg resonators with different parameters in a 30-GHz FEM are presented. The possibility of reducing the mode splitting by profiling the corrugation parameters is shown. The use of the mode splitting effect for the output power enhancement by passive compression of the double-frequency pulse generated in the FEM with such a resonator is discussed.

  12. Could test length or order affect scores on letter number sequencing of the WAIS-III and WMS-III? Ruling out effects of fatigue.

    PubMed

    Tulsky, D S; Zhu, J

    2000-11-01

    The Letter Number Sequencing subtest of the WAIS-III and WMS-III was administered at the end of the standardization edition of the WMS-III. It was not administered as part of the WAIS-III standardization battery. Nevertheless, the subtest was included in the published version of the WAIS-III. This study examines differences between examinees administered the Letter Number Sequencing subtest at three different times during a psychological battery: (1) as part of the published battery, (2) as part of the WMS-III when the WMS-III was administered as the first test in a sequence, and (3) as part of the WMS-III standardization when the WAIS-III was administered immediately preceding the WMS-III. The participants were 372 examinees ( n = 124 in each condition) who were matched on key demographic variables. A repeated measures MANOVA yielded no difference in subtest scores when administered in any of these conditions. The results show no evidence of fatigue or ordering effects on the Letter Number Sequencing subtest.

  13. Linear canonical transformations of coherent and squeezed states in the Wigner phase space. III - Two-mode states

    NASA Technical Reports Server (NTRS)

    Han, D.; Kim, Y. S.; Noz, Marilyn E.

    1990-01-01

    It is shown that the basic symmetry of two-mode squeezed states is governed by the group SP(4) in the Wigner phase space which is locally isomorphic to the (3 + 2)-dimensional Lorentz group. This symmetry, in the Schroedinger picture, appears as Dirac's two-oscillator representation of O(3,2). It is shown that the SU(2) and SU(1,1) interferometers exhibit the symmetry of this higher-dimensional Lorentz group. The mathematics of two-mode squeezed states is shown to be applicable to other branches of physics including thermally excited states in statistical mechanics and relativistic extended hadrons in the quark model.

  14. Black-hole normal modes: A WKB approach. III. The Reissner-Nordström black hole

    NASA Astrophysics Data System (ADS)

    Kokkotas, Kostas D.; Schutz, Bernard F.

    1988-06-01

    Complex frequencies of the normal modes of the Reissner-Nordström black hole are computed by two independent methods. The first is a high-order WKB approach devised by Schutz and Will and extended by Iyer and Will for the Schwarzschild case. The second is direct numerical integration using a method developed by Chandrasekhar and Detweiler, thereby extending earlier results of Gunter. The WKB results agree with the numerical ones with an error less than 1% for the lowest-order modes. For somewhat higher orders, the numerical techniques fail but the WKB method continues to give eigenfrequencies that should be reasonably accurate.

  15. Proton irradiation effects on advanced digital and microwave III-V components

    NASA Astrophysics Data System (ADS)

    Hash, G. L.; Schwank, J. R.; Shaneyfelt, M. R.; Sandoval, C. E.; Connors, M. P.; Sheridan, T. J.; Sexton, F. W.; Slayton, E. M.; Heise, J. A.; Foster, C.

    1994-01-01

    A wide range of advanced III-V components suitable for use in high-speed satellite communication systems were evaluated for displacement damage and single-event effects in high-energy, high-fluence proton environments. Transistors and integrated circuits (both digital and MMIC) were irradiated with protons at energies from 41 to 197 MeV and at fluences from 10(exp 10) to 2 x 10(exp 14) protons/sq cm. Large soft-error rates were measured for digital GaAs MESFET (3 x 10(exp -5) errors/bit-day) and heterojunction bipolar circuits (10(exp -5) errors/bit-day). No transient signals were detected from MMIC circuits. The largest degradation in transistor response caused by displacement damage was observed for 1.0-(mu)m depletion- and enhancement-mode MESFET transistors. Shorter gate length MESFET transistors and HEMT transistors exhibited less displacement-induced damage. These results show that memory-intensive GaAs digital circuits may result in significant system degradation due to single-event upset in natural and man-made space environments. However, displacement damage effects should not be a limiting factor for fluence levels up to 10(exp 14) protons/sq cm (equivalent to total doses in excess of 10 Mrad(GaAs)).

  16. Proton irradiation effects on advanced digital and microwave III-V components

    SciTech Connect

    Hash, G.L.; Schwank, J.R.; Shaneyfelt, M.R.; Sandoval, C.E.; Connors, M.P.; Sheridan, T.J.; Sexton, F.W.; Slayton, E.M.; Heise, J.A.; Foster, C.

    1994-09-01

    A wide range of advanced III-V components suitable for use in high-speed satellite communication systems were evaluated for displacement damage and single-event effects in high-energy, high-fluence proton environments. Transistors and integrated circuits (both digital and MMIC) were irradiated with protons at energies from 41 to 197 MeV and at fluences from 10{sup 10} to 2 {times} 10{sup 14} protons/cm{sup 2}. Large soft-error rates were measured for digital GaAs MESFET (3 {times} 10{sup {minus}5} errors/bit-day) and heterojunction bipolar circuits (10{sup {minus}5} errors/bit-day). No transient signals were detected from MMIC circuits. The largest degradation in transistor response caused by displacement damage was observed for 1.0-{mu}m depletion- and enhancement-mode MESFET transistors. Shorter gate length MESFET transistors and HEMT transistors exhibited less displacement-induced damage. These results show that memory-intensive GaAs digital circuits may result in significant system degradation due to single-event upset in natural and man-made space environments. However, displacement damage effects should not be a limiting factor for fluence levels up to 10{sup 14} protons/cm{sup 2} [equivalent to total doses in excess of 10 Mrad(GaAs)].

  17. Development and Application of Benchmark Examples for Mixed-Mode I/II Quasi-Static Delamination Propagation Predictions

    NASA Technical Reports Server (NTRS)

    Krueger, Ronald

    2012-01-01

    The development of benchmark examples for quasi-static delamination propagation prediction is presented and demonstrated for a commercial code. The examples are based on finite element models of the Mixed-Mode Bending (MMB) specimen. The examples are independent of the analysis software used and allow the assessment of the automated delamination propagation prediction capability in commercial finite element codes based on the virtual crack closure technique (VCCT). First, quasi-static benchmark examples were created for the specimen. Second, starting from an initially straight front, the delamination was allowed to propagate under quasi-static loading. Third, the load-displacement relationship from a propagation analysis and the benchmark results were compared, and good agreement could be achieved by selecting the appropriate input parameters. Good agreement between the results obtained from the automated propagation analysis and the benchmark results could be achieved by selecting input parameters that had previously been determined during analyses of mode I Double Cantilever Beam and mode II End Notched Flexure specimens. The benchmarking procedure proved valuable by highlighting the issues associated with choosing the input parameters of the particular implementation. Overall the results are encouraging, but further assessment for mixed-mode delamination fatigue onset and growth is required.

  18. Effect of the medium and the formation of nanostructures on deexcitation of electronic excitation of Eu(III) and Tb(III) chelates

    NASA Astrophysics Data System (ADS)

    Sveshnikova, E. B.; Dudar, S. S.; Shablya, A. V.; Ermolaev, V. L.

    2006-10-01

    The intensity I lum and lifetime τlum of the luminescence of complexes of Eu(III) and Tb(III) ions with β-diketones and o-phenanthroline in water-ethanol solutions of these ligands have been analyzed as functions of the concentrations of ligand, luminescing lanthanide ions, and added ions causing columinescence and of the solvent deuteration. It is shown that the formation of nanostructures from Ln complexes and their coarsening leads to an increase in τlum of Eu(III) and Tb(III) and that this increase is due to the suppression of both photochemical deexcitation of these ions and transfer of their electronic excitation energy to OH vibrations of water molecules. The disappearance of the dependence of I lum of Eu(III) on deuteration of water-ethanol solutions of n-methoxybenzoyltrifluoracetone + o-phenanthroline caused by adding Gd(III) ions is explained by the shift of the equilibrium of formation of complexes of Ln chelates to neutral hydrophoblic forms corresponding to the formation of nanostructures of these chelates in the solution. The differences in effect of La(III) and Gd(III) ions on I lum and τlum of Eu(III) and Tb(III) complexes are explained. It is shown that the widely discussed effect of columinescence not only results from the energy migration in mixed structures of Eu or Tb complexes and Gd complexes but is also due to a large extent to the decrease in τlum of Eu(III) or Tb(III) caused by their incorporation into nanostructures.

  19. The effects of different modes of supervision on vigilance behaviour.

    PubMed

    Putz, V R

    1975-05-01

    Experiment I was run to determine if a closed-circuit television and a one-way window mode of supervision were as effective as the direct physical presence of an experimenter in inducing enhanced levels of signal detection in a Mackworth-type vigilance task. A control condition of complete subject privacy was also examined. The results indicated that both the television and the window conditions had a positive effect on overall performance which was similar to that observed in the experimenter-presence condition; however, the performance decrement over the 90 min vigil was equivalent for the four modes. A second experiment involving the variable of camera position with an addition of a fourth 30 min. period yielded no significant differences between the camera positions, but overall performance in the television condition was again better than in the control condition. This study suggested that performance can be enhanced even without the physical presence of the experimenter. PMID:1156737

  20. Protective effect of antithrombin III in acute experimental pancreatitis in rats.

    PubMed

    Bleeker, W K; Agterberg, J; Rigter, G; Hack, C E; Gool, J V

    1992-02-01

    In the present study we investigated the therapeutic action of antithrombin III (AT III) in taurocholate-induced experimental pancreatitis with high lethality in rats. High-dose AT III treatment greatly improved the survival rate not only when given as pretreatment but also when given 2 hr after induction. No favorable effect on survival rate was observed on administration after 5 hr. Both intravascular and intraperitoneal AT III administration locally restored decreased AT III levels in the peritoneal cavity and increased plasma AT III to supranormal levels. The primary pancreatic insult seemed to be unaffected by the treatment, because neither the rise in plasma lipase nor the development of ascites or the extension of the pancreatic necrosis were diminished. Because heparin pretreatment of the rats was also effective, the mechanism of the beneficial action was probably mediated by inhibition of the proteases of the coagulation cascade, thereby preventing intravascular coagulation in the pancreas and distant organs and subsequent systemic complications. The high efficacy of AT III treatment in this experimental model may stimulate clinical studies evaluating the efficacy of AT III treatment in an early stage of acute pancreatitis.

  1. Microstructural effects on fracture toughness of polycrystalline ceramics in combined mode I and mode II loading

    NASA Technical Reports Server (NTRS)

    Singh, D.; Shetty, D. K.

    1988-01-01

    Fracture toughness of polycrystalline alumina and ceria partially-stabilized tetragonal zirconia (CeO2-TZP) ceramics were assessed in combined mode I and mode II loading using precracked disk specimens in diametral compression. Stress states ranging from pure mode I, combined mode I and mode II, and pure mode II were obtained by aligning the center crack at specific angles relative to the loading diameter. The resulting mixed-mode fracture toughness envelope showed significant deviation to higher fracture toughness in mode II relative to the predictions of the linear elastic fracture mechanics theory. Critical comparison with corresponding results on soda-lime glass and fracture surface observations showed that crack surface resistance arising from grain interlocking and abrasion was the main source of the increased fracture toughness in mode II loading of the polycrystalline ceramics. The normalized fracture toughness for pure mode II loading, (KII/KIc), increased with increasing grain size for the CeO2-TZP ceramics. Quantitative fractography confirmed an increased percentage of transgranular fracture of the grains in mode II loading.

  2. Membrane damage by cytolysin A-III: effects of monovalent and divalent cations

    SciTech Connect

    Liu, J.; Blumenthal, K.M.

    1987-05-01

    The effects of monovalent and divalent cations on the hemolytic activity of Cerebratulus lacteus toxin A-III were studied. In PBS buffer, A-III activity is strongly inhibited by increasing the osmotic pressure with sodium chloride but not with sucrose. Different salts, whether permeant or impermeant show qualitatively similar inhibitory effects. In low ionic strength isotonic buffer the hemolytic activity of A-III is remarkably increased, the HC50 being shifted from 2 ..mu..g/ml to 20-30 ng/ml in Hepes-sucrose. This corresponds to a 50-100 fold increase in activity. The divalent cations Zn/sup 2 +/ and Ca/sup 2 +/ also inhibit A-III activity, 0.3 mM Zn/sup 2 +/ totally abolishing A-III dependent hemolysis of human erythrocytes. Analogous studies on marker release from liposomes suggested that the effect of Zn/sup 2 +/ is due to its interaction with phospholipids. Inhibition of A-III activity by both mono and divalent cations is compatible with the importance of membrane surface potential in cytolysis. Screening of the surface potential by cations decreases membrane damage by A-III. Their data suggest a direct effect of cations on membrane phospholipid and are, to their knowledge, the first to show that cytolysin activity can be enhanced by decreasing ionic strength, in contrast to data obtained previously with other cytolysins.

  3. Development and Application of Benchmark Examples for Mixed-Mode I/II Quasi-Static Delamination Propagation Predictions

    NASA Technical Reports Server (NTRS)

    Krueger, Ronald

    2012-01-01

    The development of benchmark examples for quasi-static delamination propagation prediction is presented. The example is based on a finite element model of the Mixed-Mode Bending (MMB) specimen for 50% mode II. The benchmarking is demonstrated for Abaqus/Standard, however, the example is independent of the analysis software used and allows the assessment of the automated delamination propagation prediction capability in commercial finite element codes based on the virtual crack closure technique (VCCT). First, a quasi-static benchmark example was created for the specimen. Second, starting from an initially straight front, the delamination was allowed to propagate under quasi-static loading. Third, the load-displacement as well as delamination length versus applied load/displacement relationships from a propagation analysis and the benchmark results were compared, and good agreement could be achieved by selecting the appropriate input parameters. The benchmarking procedure proved valuable by highlighting the issues associated with choosing the input parameters of the particular implementation. Overall, the results are encouraging, but further assessment for mixed-mode delamination fatigue onset and growth is required.

  4. Effects of Humidity on Non-Hermetically Packaged III-V Structures and Devices

    NASA Technical Reports Server (NTRS)

    Leon, R.; Martin, S.; Lee, T.; Okuno, J.; Ruiz, R.; Gauldin, R.; Gaidis, M.; Smith, R.

    1999-01-01

    High humidity and temperature test (known as 85/85 tests) were performed on various III-V devices and structures to determine environmental effects in non-hermetically packaged GaAs membrane mixer diodes.

  5. Effects of ionic strength and fulvic acid on adsorption of Tb(III) and Eu(III) onto clay

    NASA Astrophysics Data System (ADS)

    Poetsch, Maria; Lippold, Holger

    2016-09-01

    High salinity and natural organic matter are both known to facilitate migration of toxic or radioactive metals in geochemical systems, but little is known on their combined effect. We investigated complexation of Tb(III) and Eu(III) (as analogues for trivalent actinides) with fulvic acid and their adsorption onto a natural clay in the presence of NaCl, MgCl2 and CaCl2 up to very high ionic strengths. 160Tb, 152Eu and 14C-labelled fulvic acid were employed as radiotracers, allowing investigations at very low concentrations according to probable conditions in far-field scenarios of nuclear waste repositories. A combined Kd approach (Linear Additive Model) was tested for suitability in predicting solid-liquid distribution of metals in the presence of organic matter based on the interactions in the constituent subsystems. In this analysis, it could be shown that high ionic strength does not further enhance the mobilizing potential of humic matter. A quantitative reproduction of the influence of fulvic acid failed for most systems under study. Assumptions and limitations of the model are discussed.

  6. Effects of ionic strength and fulvic acid on adsorption of Tb(III) and Eu(III) onto clay.

    PubMed

    Poetsch, Maria; Lippold, Holger

    2016-09-01

    High salinity and natural organic matter are both known to facilitate migration of toxic or radioactive metals in geochemical systems, but little is known on their combined effect. We investigated complexation of Tb(III) and Eu(III) (as analogues for trivalent actinides) with fulvic acid and their adsorption onto a natural clay in the presence of NaCl, MgCl2 and CaCl2 up to very high ionic strengths. (160)Tb, (152)Eu and (14)C-labelled fulvic acid were employed as radiotracers, allowing investigations at very low concentrations according to probable conditions in far-field scenarios of nuclear waste repositories. A combined Kd approach (Linear Additive Model) was tested for suitability in predicting solid-liquid distribution of metals in the presence of organic matter based on the interactions in the constituent subsystems. In this analysis, it could be shown that high ionic strength does not further enhance the mobilizing potential of humic matter. A quantitative reproduction of the influence of fulvic acid failed for most systems under study. Assumptions and limitations of the model are discussed. PMID:27454893

  7. Magnetospheric filter effect for Pc 3 Alfven mode waves

    NASA Technical Reports Server (NTRS)

    Zhang, X.; Comfort, R. H.; Gallagher, D. L.; Green, J. L.; Musielak, Z. E.; Moore, T. E.

    1994-01-01

    We present a ray-tracing study of the propagation of Pc 3 Alfven mode waves originating at the dayside magnetopause. This study reveals interesting features of a magnetospheric filter effect for these waves. Pc 3 Alfven mode waves cannot penetrate to low Earth altitudes unless the wave frequency is below approximately 30 mHz. Configurations of the dispersion curves and the refractive index show that the gyroresonance and pseudo-cutoff introduced by the heavy ion O(+) block the waves. When the O(+) concentration is removed from the plasma composition, the barriers caused by the O(+) no longer exist, and waves with much higher frequencies than 30 mHz can penetrate to low altitudes. The result that the 30 mHz or lower frequency Alfven waves can be guided to low altitudes agrees with ground-based power spectrum observations at high latitudes.

  8. Magnetospheric filter effect for Pc 3 Alfven mode waves

    NASA Technical Reports Server (NTRS)

    Zhang, X.; Comfort, R. H.; Gallagher, D. L.; Green, J. L.; Musielak, Z. E.; Moore, T. E.

    1995-01-01

    We present a ray-tracing study of the propagation of Pc 3 Alfven mode waves originating at the dayside magnetopause. This study reveals interesting features of magnetospheric filter effect for these waves. Pc 3 Alfven mode waves cannot penetrate to low Earth altitudes unless the wave frequency is below approximately 30 mHz. Configurations of the dispersion curves and the refractive index show that the gyroresonance and pseudo-cutoff introduced by the heavy ion O(+) block the waves. When the O(+) concentration is removed from the plasma composition, the barriers caused by the O(+) no longer exist, and waves with much higher frequencies than 30 mHz can penetrate to low altitudes. The result that the 30 mHz or lower frequency Alfven waves can be guided to low altitudes agrees with ground-based power spectrum observation at high altitudes.

  9. Curvature effects on the dynamics of tearing modes in tokamaks

    NASA Astrophysics Data System (ADS)

    Lütjens, Hinrich; Luciani, Jean-François; Garbet, Xavier

    2001-10-01

    The curvature effects on the dynamics of magnetic island evolution in tokamaks are investigated both theoretically and numerically. By taking into account perpendicular and parallel heat diffusion, a new dispersion relation is derived for tearing modes that match the linear and nonlinear results. This evolution equation allows a quantitative description over the whole range of island sizes. It predicts a nonlinear instability, i.e., growing magnetic islands in linearly stable magnetic configurations. All these predictions are in excellent agreement with full tridimensional linear and nonlinear magnetohydrodynamic (MHD) computations with the latest version of XTOR [K. Lerbinger and J. F. Luciani, J. Comput. Phys. 97, 444 (1991)]. These results have important consequences on the onset of neoclassical tearing modes because they predict a resistive MHD threshold.

  10. Impurity effects on trapped electron mode in tokamak plasmas

    NASA Astrophysics Data System (ADS)

    Du, Huarong; Wang, Zheng-Xiong; Dong, J. Q.

    2016-07-01

    The effects of impurity ions on the trapped electron mode (TEM) in tokamak plasmas are numerically investigated with the gyrokinetic integral eigenmode equation. It is shown that in the case of large electron temperature gradient ( η e ), the impurity ions have stabilizing effects on the TEM, regardless of peaking directions of their density profiles for all normalized electron density gradient R / L n e . Here, R is the major radius and L n e is the electron density gradient scale length. In the case of intermediate and/or small η e , the light impurity ions with conventional inwardly (outwardly) peaked density profiles have stabilizing effects on the TEM for large (small) R / L n e , while the light impurity ions with steep inwardly (outwardly) peaked density profiles can destabilize the TEM for small (large) R / L n e . Besides, the TEM driven by density gradient is stabilized (destabilized) by the light carbon or oxygen ions with inwardly (outwardly) peaked density profiles. In particular, for flat and/or moderate R / L n e , two independent unstable modes, corresponding respectively to the TEM and impurity mode, are found to coexist in plasmas with impurity ions of outwardly peaked density profiles. The high Z tungsten impurity ions play a stronger stabilizing role in the TEM than the low Z impurity ions (such as carbon and oxygen) do. In addition, the effects of magnetic shear and collision on the TEM instability are analyzed. It is shown that the collisionality considered in this work weakens the trapped electron response, leading to a more stable TEM instability, and that the stabilizing effects of the negative magnetic shear on the TEM are more significant when the impurity ions with outwardly peaked density profile are taken into account.

  11. Experimental and Theoretical Studies on Biologically Active Lanthanide (III) Complexes

    NASA Astrophysics Data System (ADS)

    Kostova, I.; Trendafilova, N.; Georgieva, I.; Rastogi, V. K.; Kiefer, W.

    2008-11-01

    The complexation ability and the binding mode of the ligand coumarin-3-carboxylic acid (HCCA) to La(III), Ce(III), Nd(III), Sm(III), Gd(III) and Dy(III) lanthanide ions (Ln(III)) are elucidated at experimental and theoretical level. The complexes were characterized using elemental analysis, DTA and TGA data as well as 1H NMR and 13C NMR spectra. FTIR and Raman spectroscopic techniques as well as DFT quantum chemical calculations were used for characterization of the binding mode and the structures of lanthanide(III) complexes of HCCA. The metal—ligand binding mode is predicted through molecular modeling and energy estimation of different Ln—CCA structures using B3LYP/6-31G(d) method combined with a large quasi-relativistic effective core potential for lanthanide ion. The energies obtained predict bidentate coordination of CCA- to Ln(III) ions through the carbonylic oxygen and the carboxylic oxygen. Detailed vibrational analysis of HCCA, CCA- and Ln(III) complexes based on both calculated and experimental frequencies confirms the suggested metal—ligand binding mode. The natural bonding analysis predicts strongly ionic character of the Ln(III)-CCA bonding in the- complexes studied. With the relatively resistant tumor cell line K-562 we obtained very interesting in-vitro results which are in accordance with our previously published data concerning the activity of lanthanide(III) complexes with other coumarin derivatives.

  12. Scaling of divertor power footprint width in RF-heated type-III ELMy H-mode on the EAST superconducting tokamak

    NASA Astrophysics Data System (ADS)

    Wang, L.; Guo, H. Y.; Xu, G. S.; Liu, S. C.; Gan, K. F.; Wang, H. Q.; Gong, X. Z.; Liang, Y.; Zou, X. L.; Hu, J. S.; Chen, L.; Xu, J. C.; Liu, J. B.; Yan, N.; Zhang, W.; Chen, R.; Shao, L. M.; Ding, S.; Hu, G. H.; Feng, W.; Zhao, N.; Xiang, L. Y.; Liu, Y. L.; Li, Y. L.; Sang, C. F.; Sun, J. Z.; Wang, D. Z.; Ding, H. B.; Luo, G. N.; Chen, J. L.; Gao, X.; Hu, L. Q.; Wan, B. N.; Li, J.; the EAST Team

    2014-11-01

    Dedicated experiments for the scaling of divertor power footprint width have been performed in the ITER-relevant radio-frequency (RF)-heated H-mode scheme under the lower single null, double null and upper single null divertor configurations in the Experimental Advanced Superconducting Tokamak (EAST) under lithium wall coating conditioning. A strong inverse scaling of the edge localized mode (ELM)-averaged power fall-off width with the plasma current (equivalently the poloidal field) has been demonstrated for the attached type-III ELMy H-mode as λq \\propto Ip-1.05 by various heat flux diagnostics including the divertor Langmuir probes (LPs), infra-red (IR) thermograph and reciprocating LPs on the low-field side. The IR camera and divertor LP measurements show that λq,IR ≈ {λq,div{-LPs}}/{1.3}=1.15Bp,omp-1.25 , in good agreement with the multi-machine scaling trend during the inter-ELM phase between type-I ELMs or ELM-free enhanced Dα (EDA). H-mode. However, the magnitude is nearly doubled, which may be attributed to the different operation scenarios or heating schemes in EAST, i.e., dominated by electron heating. It is also shown that the type-III ELMs only broaden the power fall-off width slightly, and the ELM-averaged width is representative for the inter-ELM period. Furthermore, the inverse Ip (Bp) scaling appears to be independent of the divertor configurations in EAST. The divertor power footprint integral width, fall-off width and dissipation width derived from EAST IR camera measurements follow the relation, λint ≅ λq + 1.64S, yielding λ_intEAST =(1.39+/- 0.03)λqEAST +(0.97+/- 0.35) mm . Detailed analysis of these three characteristic widths was carried out to shed more light on their extrapolation to ITER.

  13. The Emotional Child Witness Effect Survives Presentation Mode.

    PubMed

    Melinder, Annika; Burrell, Lisa; Eriksen, Maria Olaussen; Magnussen, Svein; Wessel, Ellen

    2016-01-01

    The emotional witness effect - the phenomenon whereby people are affected by the emotional manner in which a witness presents testimony - constitutes a possible source of wrongful decisions in legal contexts. One stereotypical view of abused children is that they should be sad when talking about their experiences of maltreatment, whereas children may in fact express a variety of emotional expressions when talking about abusive events. This raises the question as to whether there is an optimal mode in which to present child victim testimony that could reduce the possible influence of displayed emotions. In the present study, mock police interviews were carried out with female child actors, role-playing the victims of physical abuse by their stepfather, telling the same story with four emotional expressions (neutral, sad, angry, or positive). Laypersons (N = 465) were presented with the interviews as transcripts with the emotional reactions of the child witness noted, audio recordings, or videotaped recordings. Participants then rated the credibility of the victim witness. Replicating previous results, the "sad" expression elicited the highest credibility ratings across all modes of presentations. Presentation mode affected ratings of credibility, with the transcript versions resulting in the highest ratings. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26990221

  14. The Escherichia coli modE gene: effect of modE mutations on molybdate dependent modA expression.

    PubMed

    McNicholas, P M; Chiang, R C; Gunsalus, R P

    1996-11-15

    The Escherichia coli modABCD operon, which encodes a high-affinity molybdate uptake system, is transcriptionally regulated in response to molybdate availability by ModE. Here we describe a highly effective enrichment protocol, applicable to any gene with a repressor role, and establish its application in the isolation of transposon mutations in modE. In addition we show that disruption of the ModE C-terminus abolishes derepression in the absence of molybdate, implying this region of ModE controls the repressor activity. Finally, a mutational analysis of a proposed molybdate binding motif indicates that this motif does not function in regulating the repressor activity of ModE.

  15. Effects of damping on mode shapes, volume 1

    NASA Technical Reports Server (NTRS)

    Gates, R. M.

    1977-01-01

    Displacement, velocity, and acceleration admittances were calculated for a realistic NASTRAN structural model of space shuttle for three conditions: liftoff, maximum dynamic pressure and end of solid rocket booster burn. The realistic model of the orbiter, external tank, and solid rocket motors included the representation of structural joint transmissibilities by finite stiffness and damping elements. Methods developed to incorporate structural joints and their damping characteristics into a finite element model of the space shuttle, to determine the point damping parameters required to produce realistic damping in the primary modes, and to calculate the effect of distributed damping on structural resonances through the calculation of admittances.

  16. Extended recency effect extended: blocking, presentation mode, and retention interval.

    PubMed

    Glidden, L M; Pawelski, C; Mar, H; Zigman, W

    1979-07-01

    The effect of blocking of stimulus items on the free recall of EMR adolescents was examined. In Experiment 1 a multitrial free-recall list of 15 pictures was presented either simultaneously in groups of 3, or sequentially, one at a time. Consistent ordering was used in both conditions, so that on each trial, each item in each set of 3 pictures was presented contiguously with the other 2 items from that set. In addition, recall came immediately or after a filled or unfilled delay of 24.5 seconds. Results showed that simultaneous presentation led to higher recall, subjective organization, and clustering than did sequential presentation, but analysis of serial-position curves showed a much reduced extended recency effect in comparison with previous studies. Experiment 2 was designed to determine whether the cause of the reduced extended recency was the use of pictures rather than words as stimuli. Stimuli were presented either as pictures, as pictures with auditory labels, or as words with auditory labels, with both simultaneous and consistent ordering for all conditions. Results indicated a strong extended recency effect for all groups, eliminating presentation mode as a causal factor in the data of Experiment 1. We concluded that blocking leads to increased organization and recall over a variety of presentation modes, rates, and block sizes.

  17. Reflective liquid crystal light valve with hybrid field effect mode

    NASA Technical Reports Server (NTRS)

    Boswell, Donald D. (Inventor); Grinberg, Jan (Inventor); Jacobson, Alexander D. (Inventor); Myer, Gary D. (Inventor)

    1977-01-01

    There is disclosed a high performance reflective mode liquid crystal light valve suitable for general image processing and projection and particularly suited for application to real-time coherent optical data processing. A preferred example of the device uses a CdS photoconductor, a CdTe light absorbing layer, a dielectric mirror, and a liquid crystal layer sandwiched between indium-tin-oxide transparent electrodes deposited on optical quality glass flats. The non-coherent light image is directed onto the photoconductor; this reduces the impedance of the photoconductor, thereby switching the AC voltage that is impressed across the electrodes onto the liquid crystal to activate the device. The liquid crystal is operated in a hybrid field effect mode. It utilizes the twisted nematic effect to create a dark off-state (voltage off the liquid crystal) and the optical birefringence effect to create the bright on-state. The liquid crystal thus modulates the polarization of the coherent read-out or projection light responsively to the non-coherent image. An analyzer is used to create an intensity modulated output beam.

  18. Iron (III) Matrix Effects on Mineralization and Immobilization of Actinides

    SciTech Connect

    Cynthia-May S. Gong; Tyler A. Sullens; Kenneth R. Czerwinski

    2006-01-01

    Abstract - A number of models for the Yucca Mountain Project nuclear waste repository use studies of actinide sorption onto well-defined iron hydroxide materials. In the case of a waste containment leak, however, a complex interaction between dissolved waste forms and failed containment vessel components can lead to immediate precipitation of migratory iron and uranyl in the silicate rich near-field environment. Use of the Fe(III) and UO22+ complexing agent acetohydroxamic acid (AHA) as a colorimetric agent for visible spectrophotometry is well-known. Using the second derivative of these spectra a distinct shift in iron complexation in the presence of silicate is seen that is not seen with uranyl or alone. Silica also decreases the ability of uranyl and ferric solutions to absorb hydroxide, hastening precipitation. These ferric silicate precipitates are highly amorphous and soluble. Precipitates formed in the presence of uranyl below ~1 mol% exhibit lower solubility than precipitates from up to 50 mol % and of uranyl silicates alone.

  19. Testing mode and surface treatment effects on dentin bonding.

    PubMed

    Drummond, J L; Sakaguchi, R L; Racean, D C; Wozny, J; Steinberg, A D

    1996-12-01

    The goal of this project was to evaluate the effect of the following variables on shear dentin-bonding test results: mode of testing (cyclic fatigue versus static loading), surface treatments (32% phosphoric acid, 10% phosphoric acid, and no treatment [unetched]), and type of shear test (traditional planar versus push-out). All teeth were stored in distilled water and tested in a shear mode at a loading rate of 2 mm/ min. The specimens were loaded in static or cycled for 1000 cycles using a staircase approach or until fracture, whichever occurred first. On samples with etched dentin surfaces, the push-out test did not demonstrate a significant difference in measured bond strength when compared with results from the planar test, although sample preparation was more labor-intensive. The bond strength resulting from cyclic fatigue of the etched specimens was approximately 51% of the static loading value. Ten percent phosphoric acid was as effective as 32% phosphoric acid for dentin bonding. Finite-element analysis indicated that the traditional planar shear test produces flexure of the specimen and high tensile stress magnitudes within the resin bonding layer. The push-out test produces elevated compressive stresses localized in the composite along the circumference of the punch. Shear stresses in the resin bonding layer are similar for both testing methods at the same loading element contact force.

  20. The Games Children Play III: More Comments on Effective Teaching

    ERIC Educational Resources Information Center

    Humphries, Charlotte A.; Ashy, Madge

    2013-01-01

    In the years since the authors published two articles with tips for effective teaching, they have acquired and developed more advice and impressions on teaching. This article presents ideas that can help physical educators become increasingly effective in their teaching.

  1. Mode Transitions in Magnetically Shielded Hall Effect Thrusters

    NASA Technical Reports Server (NTRS)

    Sekerak, Michael J.; Longmier, Benjamin W.; Gallimore, Alec D.; Huang, Wensheng; Kamhawi, Hani; Hofer, Richard R.; Jorns, Benjamin A.; Polk, James E.

    2014-01-01

    A mode transition study is conducted in magnetically shielded thrusters where the magnetic field magnitude is varied to induce mode transitions. Three different oscillatory modes are identified with the 20-kW NASA-300MS-2 and the 6-kW H6MS: Mode 1) global mode similar to unshielded thrusters at low magnetic fields, Mode 2) cathode oscillations at nominal magnetic fields, and Mode 3) combined spoke, cathode and breathing mode oscillations at high magnetic fields. Mode 1 exhibits large amplitude, low frequency (1-10 kHz), breathing mode type oscillations where discharge current mean value and oscillation amplitude peak. The mean discharge current is minimized while thrust-to-power and anode efficiency are maximized in Mode 2, where higher frequency (50-90 kHz), low amplitude, cathode oscillations dominate. Thrust is maximized in Mode 3 and decreases by 5-6% with decreasing magnetic field strength. The presence or absence of spokes and strong cathode oscillations do not affect each other or discharge current. Similar to unshielded thrusters, mode transitions and plasma oscillations affect magnetically shielded thruster performance and should be characterized during system development.

  2. Application of failure mode and effects analysis (FMEA) to pretreatment phases in tomotherapy.

    PubMed

    Broggi, Sara; Cantone, Marie Claire; Chiara, Anna; Di Muzio, Nadia; Longobardi, Barbara; Mangili, Paola; Veronese, Ivan

    2013-09-06

    The aim of this paper was the application of the failure mode and effects analysis (FMEA) approach to assess the risks for patients undergoing radiotherapy treatments performed by means of a helical tomotherapy unit. FMEA was applied to the preplanning imaging, volume determination, and treatment planning stages of the tomotherapy process and consisted of three steps: 1) identification of the involved subprocesses; 2) identification and ranking of the potential failure modes, together with their causes and effects, using the risk probability number (RPN) scoring system; and 3) identification of additional safety measures to be proposed for process quality and safety improvement. RPN upper threshold for little concern of risk was set at 125. A total of 74 failure modes were identified: 38 in the stage of preplanning imaging and volume determination, and 36 in the stage of planning. The threshold of 125 for RPN was exceeded in four cases: one case only in the phase of preplanning imaging and volume determination, and three cases in the stage of planning. The most critical failures appeared related to (i) the wrong or missing definition and contouring of the overlapping regions, (ii) the wrong assignment of the overlap priority to each anatomical structure, (iii) the wrong choice of the computed tomography calibration curve for dose calculation, and (iv) the wrong (or not performed) choice of the number of fractions in the planning station. On the basis of these findings, in addition to the safety strategies already adopted in the clinical practice, novel solutions have been proposed for mitigating the risk of these failures and to increase patient safety.

  3. Retrieval Mode Distinguishes the Testing Effect from the Generation Effect

    ERIC Educational Resources Information Center

    Karpicke, Jeffrey D.; Zaromb, Franklin M.

    2010-01-01

    A series of four experiments examined the effects of generation vs. retrieval practice on subsequent retention. Subjects were first exposed to a list of target words. Then the subjects were shown the targets again intact for Read trials or they were shown fragments of the targets. Subjects in Generate conditions were told to complete the fragments…

  4. The effect of initial conditions on the electromagnetic radiation generation in type III solar radio bursts

    SciTech Connect

    Schmitz, H.; Tsiklauri, D.

    2013-06-15

    Extensive particle-in-cell simulations of fast electron beams injected in a background magnetised plasma with a decreasing density profile were carried out. These simulations were intended to further shed light on a newly proposed mechanism for the generation of electromagnetic waves in type III solar radio bursts [D. Tsiklauri, Phys. Plasmas, 18, 052903 (2011)]. The numerical simulations were carried out using different density profiles and fast electron distribution functions. It is shown that electromagnetic L and R modes are excited by the transverse current, initially imposed on the system. In the course of the simulations, no further interaction of the electron beam with the background plasma could be observed.

  5. NGF has opposing effects on Na+ channel III and SNS gene expression in spinal sensory neurons.

    PubMed

    Black, J A; Langworthy, K; Hinson, A W; Dib-Hajj, S D; Waxman, S G

    1997-07-01

    Following sciatic nerve transection, the expression of sodium channel III (alpha-III) transcripts increases and SNS (alpha-SNS) transcripts decreases in small (< 25 microns diameter) dorsal root ganglion (DRG) neurons, which may reflect an interruption of retrograde transport of peripherally derived factor(s) involved in the regulation of these channels. To test the hypothesis that the neurotrophin nerve growth factor (NGF), which is abundant in peripheral targets, participates in the modulation of the expression of these sodium channel transcripts, we examined the hybridization signal of alpha-SNS and alpha-III mRNAs in small DRG neurons from adult rats that had been dissociated and maintained for 7 days in the absence or presence of exogenous NGF. Neurons maintained in control (no added NGF) cultures showed changes in alpha-III and alpha-SNS hybridization signal similar to those induced by axotomy, with increased alpha-III mRNA levels and decreased alpha-SNS mRNA levels, compared with those observed in small DRG neurons at 1 day in vitro. The addition of exogenous NGF to DRG cultures attenuated these alterations in transcript levels, decreasing alpha-III mRNA and increasing alpha-SNS mRNA expression. These results suggest that NGF participates in the regulation of membrane excitability in small DRG neurons by pathways that include opposing effects on different sodium channel genes. PMID:9243635

  6. Dislocation effects in FinFETs for different III-V compound semiconductors

    NASA Astrophysics Data System (ADS)

    Hur, Ji-Hyun; Jeon, Sanghun

    2016-04-01

    While Si-based devices are facing the limits of scaling, III-V materials, having high mobility, have attracted more and more attention. However, their advantages are obtained by ignoring the drawbacks of inevitably present dislocations. In this paper, we present a theoretical model that describes the degradation in carrier mobility caused by these inevitable charged dislocations in nanometer-sized, quantum-confined III-V compound semiconductor fin-shaped field effect transistors. We conclude that the Fermi-level pinning effect needs to be resolved to give carriers high enough energy (Fermi energy in the channel) to effectively ignore Coulomb scattering of charges at dislocations in a channel made by III-V compound semiconductors.

  7. Effectiveness of Urban Shelter-in-Place. III: Commercial Districts

    SciTech Connect

    Chan, Wanyu R.; Chan, Wanyu R.; Nazaroff, William W.; Price, Phillip N.; Gadgil, Ashok J.

    2007-12-28

    In the event of a toxic chemical release to the atmosphere, shelter-in-place (SIP) is an emergency response option available to protect public health. This paper is the last in a three-part series that examines the effectiveness of SIP at reducing adverse health effects in communities. We model a hypothetical chemical release in an urban area, and consider SIP effectiveness in protecting occupants of commercial buildings. Building air infiltration rates are predicted from empirical data using an existing model. We consider the distribution of building air infiltration rates both with mechanical ventilation systems turned off and with the systems operating. We also consider the effects of chemical sorption to indoor surfaces and nonlinear chemical dose-response relationships. We find that commercial buildings provide effective shelter when ventilation systems are off, but that any delay in turning off ventilation systems can greatly reduce SIP effectiveness. Using a two-zone model, we find that there can be substantial benefit by taking shelter in the inner parts of a building that do not experience direct air exchange with the outdoors. Air infiltration rates vary substantially among buildings and this variation is important in quantifying effectiveness for emergency response. Community-wide health metrics, introduced in the previous papers in this series, can be applied in pre-event planning and to guide real-time emergency response.

  8. Gd(III) doping effect on magnetization and water proton relaxivities in ultra small iron oxide nanoparticles

    NASA Astrophysics Data System (ADS)

    Choi, Eun Sook; Xu, Wenlong; Baek, Myung Ju; Park, Ja Young; Kim, Joo Hyun; Chang, Yongmin; Kim, Tae Jeong; Lee, Gang Ho

    2013-07-01

    Two samples of ultra small Gd(III) doped iron oxide nanoparticles were prepared to investigate Gd(III) doping effect on longitudinal (r1) and transverse (r2) water proton relaxivities. Gd(III) doping mole percents were 0.2 and 0.4 for samples 1 and 2, respectively. Average particle diameters were 2.5 to 2.1 nm for samples 1 and 2, respectively. Reduced r1 and r2 values were observed in both samples. We attributed this to reduced magnetizations arising from opposing effect of Gd(III) to net magnetizations of Fe(III)/Fe(II) in oxide nanoparticles.

  9. Diamagnetic drift effects on the low-n magnetohydrodynamic modes at the high mode pedestal with plasma rotation

    NASA Astrophysics Data System (ADS)

    Zheng, L. J.; Kotschenreuther, M. T.; Valanju, P.

    2014-06-01

    The diamagnetic drift effects on the low-n magnetohydrodynamic instabilities at the high-mode (H-mode) pedestal are investigated in this paper with the inclusion of bootstrap current for equilibrium and rotation effects for stability, where n is the toroidal mode number. The AEGIS (Adaptive EiGenfunction Independent Solutions) code [L. J. Zheng and M. T. Kotschenreuther, J. Comp. Phys. 211 (2006)] is extended to include the diamagnetic drift effects. This can be viewed as the lowest order approximation of the finite Larmor radius effects in consideration of the pressure gradient steepness at the pedestal. The H-mode discharges at Jointed European Torus is reconstructed numerically using the VMEC code [P. Hirshman and J. C. Whitson, Phys. Fluids 26, 3553 (1983)], with bootstrap current taken into account. Generally speaking, the diamagnetic drift effects are stabilizing. Our results show that the effectiveness of diamagnetic stabilization depends sensitively on the safe factor value (qs) at the safety-factor reversal or plateau region. The diamagnetic stabilization are weaker, when qs is larger than an integer; while stronger, when qs is smaller or less larger than an integer. We also find that the diamagnetic drift effects also depend sensitively on the rotation direction. The diamagnetic stabilization in the co-rotation case is stronger than in the counter rotation case with respect to the ion diamagnetic drift direction.

  10. Diamagnetic drift effects on the low-n magnetohydrodynamic modes at the high mode pedestal with plasma rotation

    SciTech Connect

    Zheng, L. J.; Kotschenreuther, M. T.; Valanju, P.

    2014-06-15

    The diamagnetic drift effects on the low-n magnetohydrodynamic instabilities at the high-mode (H-mode) pedestal are investigated in this paper with the inclusion of bootstrap current for equilibrium and rotation effects for stability, where n is the toroidal mode number. The AEGIS (Adaptive EiGenfunction Independent Solutions) code [L. J. Zheng and M. T. Kotschenreuther, J. Comp. Phys. 211 (2006)] is extended to include the diamagnetic drift effects. This can be viewed as the lowest order approximation of the finite Larmor radius effects in consideration of the pressure gradient steepness at the pedestal. The H-mode discharges at Jointed European Torus is reconstructed numerically using the VMEC code [P. Hirshman and J. C. Whitson, Phys. Fluids 26, 3553 (1983)], with bootstrap current taken into account. Generally speaking, the diamagnetic drift effects are stabilizing. Our results show that the effectiveness of diamagnetic stabilization depends sensitively on the safe factor value (q{sub s}) at the safety-factor reversal or plateau region. The diamagnetic stabilization are weaker, when q{sub s} is larger than an integer; while stronger, when q{sub s} is smaller or less larger than an integer. We also find that the diamagnetic drift effects also depend sensitively on the rotation direction. The diamagnetic stabilization in the co-rotation case is stronger than in the counter rotation case with respect to the ion diamagnetic drift direction.

  11. Investigation of ELM [edge localized mode] Dynamics with the Resonant Magnetic Perturbation Effects

    SciTech Connect

    Pankin, Alexei Y.; Kritz, Arnold H.

    2011-07-19

    Topics covered are: anomalous transport and E x B flow shear effects in the H-mode pedestal; RMP (resonant magnetic perturbation) effects in NSTX discharges; development of a scaling of H-mode pedestal in tokamak plasmas with type I ELMs (edge localized modes); and divertor heat load studies.

  12. Collisional effects on kinetic electromagnetic modes and associated quasilinear transport

    SciTech Connect

    Rewoldt, G.; Tang, W.M.; Hastie, R.J.

    1986-08-01

    The general procedure for the analysis of low-frequency electrostatic and electro-magnetic modes in toroidal geometry is now well known. In the collisionless limit, the relevant dynamics (e.g., trapped particles, resonances, etc.) can be treated appropriately. However, with the introduction of collisional effects, it is customary, for tractability, to employ model collision operators of varying degrees of complexity. Guided by results of earlier studies of alternative collision operators in unsheared slab geometry and in toroidal geometry, an improved model collision operator is introduced here for calculating toroidal eigenmodes. Analytic and numerical results are presented to support its relevance and to demonstrate its improvement over earlier models. The associated quasilinear particle and energy transport coefficients for each species are also calculated, and compared with the usual D/sub j/ approx. = kappa/sub j/ approx. = ..gamma../k /sub perpendicular//sup 2/ estimate.

  13. Failure mode and weakening effect of water on sandstone

    NASA Astrophysics Data System (ADS)

    Baud, Patrick; Zhu, Wenlu; Wong, Teng-Fong

    2000-07-01

    Previous studies have shown that brittle strength of a rock is generally reduced in the presence of water. However, for siliciclastic rocks, there is a paucity of data on the waterweakening behavior in the cataclastic flow regime. To compare the weakening effect of water in the brittle faulting and cataclastic flow regime, triaxial compression experiments were conducted on the Berea, Boise, Darley Dale, and Gosford sandstones (with nominal porosities ranging from 11% to 35%) under nominally dry and saturated conditions at room temperature. Inelastic behavior and failure mode of the nominal dry samples were qualitatively similar to those of water-saturated samples. At elevated pressures, shear localization was inhibited, and all the samples failed by strain hardening. The compactive yield strengths (associated with the onset of shear-enhanced compaction) in the saturated samples were lower than those in the dry samples deformed under comparable pressure conditions by 20% to 70%. The reductions of brittle strength in the presence of water ranged from 5% to 17%. The water-weakening effects were most and least significant in the Gosford and Berea sandstones, respectively. The relation between water weakening and failure mode is consistently explained by micromechanical models formulated on the basis that the specific surface energy in the presence of water is lowered than that in vacuum by the ratio λ. In accordance with the Hertzian fracture model the initial yield stress in the compactive cataclastic flow regime scales with the grain-crushing pressure, which is proportional to λ3/2. In the brittle faulting regime, damage mechanics models predict that the uniaxial compressive strength scales with λ1/2. In the presence of water the confined brittle strength is lower due to reductions of both the specific surface energy and friction coefficient.

  14. Twist effect and sensing of few mode polymer fibre Bragg gratings

    NASA Astrophysics Data System (ADS)

    Yan, Binbin; Luo, Yanhua; Bhowmik, Kishore; Rajan, Ginu; Ji, Minning; Wen, Jianxiang; Peng, Gang-Ding

    2016-01-01

    For the development of the twist sensor based on few mode polymer optical fibre (POF) gratings, we investigated the twist effect of few mode (FM) POF Bragg gratings with large twist, and found the twist effect on reflection is highly mode dependent-insignificant on the fundamental mode and considerable on higher order modes, which seems closely related to the symmetry of modal field. In addition, Bragg wavelengths of both the fundamental mode and higher modes red-shift with the twisting and blue-shift with the twist releasing, and they almost display the similar response trend without any mode dependence. Further analysis found that the red-shift of the Bragg wavelength should be attributed to the redistribution of the pre-strain applied upon the POF, activated by twist. Finally, based on the reflection response to the twist, one kind of twist sensing scheme with few mode POF gratings has been demonstrated, showing great potential as a twist sensor.

  15. Can dispersal mode predict corridor effects on plant parasites?

    SciTech Connect

    Sullivan, Lauren, L.; Johnson, Brenda, L.; Brudvig, Lars, A.; Haddad, Nick, M.

    2011-08-01

    Habitat corridors, a common management strategy for increasing connectivity in fragmented landscapes, have experimentally validated positive influences on species movement and diversity. However, long-standing concerns that corridors could negatively impact native species by spreading antagonists, such as disease, remain largely untested. Using a large-scale, replicated experiment, we evaluated whether corridors increase the incidence of plant parasites. We found that corridor impacts varied with parasite dispersal mode. Connectivity provided by corridors increased incidence of biotically dispersed parasites (galls on Solidago odora) but not of abiotically dispersed parasites (foliar fungi on S. odora and three Lespedeza spp.). Both biotically and abiotically dispersed parasites responded to edge effects, but the direction of responses varied across species. Although our results require additional tests for generality to other species and landscapes, they suggest that, when establishing conservation corridors, managers should focus on mitigating two potential negative effects: the indirect effects of narrow corridors in creating edges and direct effects of corridors in enhancing connectivity of biotically dispersed parasites.

  16. Quantitative phase-amplitude microscopy. III. The effects of noise.

    PubMed

    Paganin, D; Barty, A; McMahon, P J; Nugent, K A

    2004-04-01

    We explore the effect of noise on images obtained using quantitative phase-amplitude microscopy - a new microscopy technique based on the determination of phase from the intensity evolution of propagating radiation. We compare the predictions with experimental results and also propose an approach that allows good-quality quantitative phase retrieval to be obtained even for very noisy data.

  17. Effects of terbium (III) on signaling molecules in horseradish.

    PubMed

    Wang, Lihong; Zhang, Xuanbo; Zhou, Qing; Huang, Xiaohua

    2015-03-01

    Rare earth elements, especially terbium (Tb), are high-valence heavy metal elements that accumulate in the environment, and they show toxic effects on plants. Signaling molecules regulate many physiological and biochemical processes in plants. How rare earth elements affect signaling molecules remains largely unknown. In the present study, the effects of Tb(3+) on some extracellular and intracellular signaling molecules (gibberellic acid, abscisic acid, auxin, H2O2, and Ca(2+)) in horseradish leaves were investigated by using high-performance liquid chromatography, X-ray energy spectrometry, and transmission electron microscopy, and Tb(3+) was sprayed on the surface of leaves. Tb(3+) treatment decreased the auxin and gibberellic acid contents and increased the abscisic acid content. These changes in the contents of phytohormones (gibberellic acid, abscisic acid, and auxin) triggered excessive production of intracellular H2O2. Consequently, the increase in H2O2 content stimulated the influx of extracellular Ca(2+) and the release of Ca(2+) from Ca(2+) stores, leading to Ca(2+) overload and the resulting inhibition of physiological and biochemical processes. The effects outlined above were more evident with increasing the concentration of Tb(3+) sprayed on horseradish leaves. Our data provide a possible underlying mechanism of Tb(3+) action on plants.

  18. Photophysical effects of metal-carbon sigma bonds in ortho-metalated complexes of Ir(III) and Rh(III)

    SciTech Connect

    Sprouse, S.; King, K.A.; Spellane, P.J.; Watts, R.J.

    1984-10-31

    Dichloro-bridged dimers of the type (M(L)/sub 2/Cl)/sub 2/, where L is 2-phenylpyridine (ppy) or benzo(h)quinoline (bzq) and M is Rh(III) or Ir(III), have been characterized by /sup 13/C and /sup 1/H NMR spectroscopies and by absorption and emission spectroscopies. The NMR results confirm previous formulations of the complexes as dichloro-bridged ortho-metalated dimers in halocarbon solvents but indicate that they are cleaved to monomeric species of the type M(L)/sub 2/CIS in ligating solvents such as dimethylformamide (S = solvent). The absorption spectra of each of the complexes contain several low-energy bands which are assigned as metal-to-ligand charge-transfer (MLCT) transitions. All four of the dimers emit light following photoexcitation of their glassy solutions at 77 K. Their emission spectra and lifetimes lead to assignments of their emitting states as intraligand for the Rh(III) dimers and MLCT for the Ir(III) dimers. The Ir(III) dimers are also found to emit light following excitation at 295 K in deaerated dichloromethane. No emission is seen from the Rh(III) dimers under these conditions. Comparison of these results with previous results from studies of similar Rh(III) and Ir(III) complexes of 2,2'-bipyridine (bpy) and 1,10-phenanthroline (phen) indicates that the ortho-metalated ligands are considerably higher than bpy and phen in the spectrochemical series. In addition to raising the energy of ligand field excited states in their complexes, relative to similar bpy and phen species, they induce lower energy charge-transfer transitions. These effects are consistent with the synergistic function of the ortho-metalated ligands as both strong sigma donors and ..pi.. acceptors.

  19. THE EFFECTS OF CURRENT FLOW ON BIOELECTRIC POTENTIAL : III. NITELLA.

    PubMed

    Blinks, L R

    1936-11-20

    String galvanometer records show the effect of current flow upon the bioelectric potential of Nitella cells. Three classes of effects are distinguished. 1. Counter E.M.F'S, due either to static or polarization capacity, probably the latter. These account for the high effective resistance of the cells. They record as symmetrical charge and discharge curves, which are similar for currents passing inward or outward across the protoplasm, and increase in magnitude with increasing current density. The normal positive bioelectric potential may be increased by inward currents some 100 or 200 mv., or to a total of 300 to 400 mv. The regular decrease with outward current flow is much less (40 to 50 mv.) since larger outward currents produce the next characteristic effect. 2. Stimulation. This occurs with outward currents of a density which varies somewhat from cell to cell, but is often between 1 and 2 microa/cm.(2) of cell surface. At this threshold a regular counter E.M.F. starts to develop but passes over with an inflection into a rapid decrease or even disappearance of positive P.D., in a sigmoid curve with a cusp near its apex. If the current is stopped early in the curve regular depolarization occurs, but if continued a little longer beyond the first inflection, stimulation goes on to completion even though the current is then stopped. This is the "action current" or negative variation which is self propagated down the cell. During the most profound depression of P.D. in stimulation, current flow produces little or no counter E.M.F., the resistance of the cell being purely ohmic and very low. Then as the P.D. begins to recover, after a second or two, counter E.M.F. also reappears, both becoming nearly normal in 10 or 15 seconds. The threshold for further stimulation remains enhanced for some time, successively larger current densities being needed to stimulate after each action current. The recovery process is also powerful enough to occur even though the original

  20. Resonant magnetic perturbation effect on tearing mode dynamics

    NASA Astrophysics Data System (ADS)

    Frassinetti, L.; Olofsson, K. E. J.; Brunsell, P. R.; Drake, J. R.

    2010-03-01

    The effect of a resonant magnetic perturbation (RMP) on the tearing mode (TM) dynamics is experimentally studied in the EXTRAP T2R device. EXTRAP T2R is equipped with a set of sensor coils and active coils connected by a digital controller allowing a feedback control of the magnetic instabilities. The recently upgraded feedback algorithm allows the suppression of all the error field harmonics but keeping a selected harmonic to the desired amplitude, therefore opening the possibility of a clear study of the RMP effect on the corresponding TM. The paper shows that the RMP produces two typical effects: (1) a weak oscillation in the TM amplitude and a modulation in the TM velocity or (2) a strong modulation in the TM amplitude and phase jumps. Moreover, the locking mechanism of a TM to a RMP is studied in detail. It is shown that before the locking, the TM dynamics is characterized by velocity modulation followed by phase jumps. Experimental results are reasonably explained by simulations obtained with a model.

  1. The biological effects and possible modes of action of nanosilver.

    PubMed

    Völker, Carolin; Oetken, Matthias; Oehlmann, Jörg

    2013-01-01

    Novel physicochemical and biological properties have led to a versatile spectrum of applications for nanosized silver particles. Silver nanoparticles are applied primarily for their antimicrobial effects, and may variety of commercially available products have emerged. To better predict and prevent possible environmental impacts from silver nanoparticles that are derived from increasing production volumes and environmental release, more data on the biological effects are needed on appropriate model organisms. We examined the literature that addressed the adverse effects of silver nanoparticles on different levels of biological integration, including in vitro and in vivo test systems. Results of in vitro studies indicate a dose-dependent programmed cell death included by oxidative stress as main possible pathway of toxicity. Furthermore, silver nanoparticles may affect cellular enzymes by interference with free thiol groups and mimicry of endogenous ions. Similar mechanisms may apply for antibacterial effects produced by nonasilver. These effects are primary from the interference nanosilver has with bacterial cell membranes. Few in vivo studies have been performed to evaluated the toxic mode of action of nanosilver or to provide evidence for oxidative stress as an important mechanism of nanosilver toxicity. Organisms that are most acutely sensitive to nanosilver toxicity are the freshwater filter-freeding organisms. Both in vitro and in vivo studies have demonstrated tha silver ions released from nanoparticle surface contribute to the toxicity, and, indeed, some findings indicated a unique nanoparticles effect. For an adequate evaluation of the environmental impact of nanosilver, greater emphasis should be placed on combining mechanistic investigations that are performed in vitro, with results obtained in in vivo test systems. Future in vivo test system studies should emphasize long-term exposure scenarios. Moreover, the dietary uptake of silver nanoparticles and

  2. Effect of the transverse parasitic mode on beam performance for the ADS driver linac in China

    NASA Astrophysics Data System (ADS)

    Cheng, Peng; Pei, Shi-Lun; Wang, Jiu-Qing; Li, Zhi-Hui

    2015-05-01

    The ADS (Accelerator Driven subcritical System) driver linac in China is designed to run in CW (Continuous Wave) mode with 10 mA designed beam current. In this scenario, the beam-induced parasitic modes in the ADS driver linac may make the beam unstable or deteriorate the beam performance. To evaluate the parasitic mode effect on the beam dynamics systematically, simulation studies using the ROOT-based numerical code SMD have been conducted. The longitudinal beam instability induced by the HOMs (High Order Modes) and SOMs (Same Order Modes) has little effect on the longitudinal beam performance for the current ADS driver linac design based on the 10 MeV/325 MHz injector I from previous studies. Here the transverse parasitic mode (i.e., dipole HOM) effect on the transverse beam performance at the ADS driver linac exit is investigated. To more reasonably quantify the dipole mode effect, the multi-bunch effective emittance is introduced in this paper.

  3. Finite Larmor radius effects on the coupled trapped electron and ion temperature gradient modes

    SciTech Connect

    Sandberg, I.; Isliker, H.; Pavlenko, V. P.

    2007-09-15

    The properties of the coupled trapped electron and toroidal ion temperature gradient modes are investigated using the standard reactive fluid model and taking rigorously into account the effects attributed to the ion polarization drift and to the drifts associated with the lowest-order finite ion Larmor radius effects. In the flat density regime, where the coupling between the modes is relatively weak, the properties of the unstable modes are slightly modified through these effects. For the peak density regions, where the coupling of the modes is rather strong, these second-order drifts determine the spectra of the unstable modes near the marginal conditions.

  4. Effects of PECS Phase III Application Training on Independent Mands in Young Children with Autism

    ERIC Educational Resources Information Center

    Love, Jessica June

    2013-01-01

    The purpose of this study was to examine the effects of PECS phase III application training on independent mands in young children with autism. Participants were five children with autism ranging from ages 2 to 4 years old. A multiple baseline across participants was used to evaluate acquisition of independent correct mands across baseline and…

  5. Pulsatile Support Mode of BJUT-II Ventricular Assist Device (VAD) has Better Hemodynamic Effects on the Aorta than Constant Speed Mode: A Primary Numerical Study.

    PubMed

    Gu, Kaiyun; Gao, Bin; Chang, Yu; Zeng, Yi

    2016-01-01

    BACKGROUND BJUT-II VAD is a novel left ventricular assist device (LVADs), directly implanted into the ascending aorta. The pulsatile support mode is proposed to achieve better unloading performance than constant speed mode. However, the hemodynamic effects of this support mode on the aorta are still unclear. The aim of this study was to clarify the hemodynamic effects BJUT-II VAD under pulsatile support mode on the aorta. MATERIAL AND METHODS Computational fluid dynamics (CFD) studies, based on a patient-specific aortic geometric model, were conducted. Wall shear stress (WSS), averaged WSS (avWSS), oscillatory shear index (OSI), and averaged helicity density (Ha) were calculated to compare the differences in hemodynamic effects between pulsatile support mode and constant speed mode. RESULTS The results show that avWSS under pulsatile support mode is significantly higher than that under constant speed mode (0.955Pa vs. 0.675Pa). Similarly, the OSI value under pulsatile mode is higher than that under constant speed mode (0.104 vs. 0.057). In addition, Ha under pulsatile mode for all selected cross-sections is larger than that under constant mode. CONCLUSIONS BJUT-II VAD, under pulsatile control mode, may prevent atherosclerosis lesions and aortic remodeling. The precise effects of pulsatile support mode on atherosclerosis and aortic remodeling need to be further studied in animal experiments. PMID:27363758

  6. Pulsatile Support Mode of BJUT-II Ventricular Assist Device (VAD) has Better Hemodynamic Effects on the Aorta than Constant Speed Mode: A Primary Numerical Study

    PubMed Central

    Gu, Kaiyun; Gao, Bin; Chang, Yu; Zeng, Yi

    2016-01-01

    Background BJUT-II VAD is a novel left ventricular assist device (LVADs), directly implanted into the ascending aorta. The pulsatile support mode is proposed to achieve better unloading performance than constant speed mode. However, the hemodynamic effects of this support mode on the aorta are still unclear. The aim of this study was to clarify the hemodynamic effects BJUT-II VAD under pulsatile support mode on the aorta. Material/Methods Computational fluid dynamics (CFD) studies, based on a patient-specific aortic geometric model, were conducted. Wall shear stress (WSS), averaged WSS (avWSS), oscillatory shear index (OSI), and averaged helicity density (Ha) were calculated to compare the differences in hemodynamic effects between pulsatile support mode and constant speed mode. Results The results show that avWSS under pulsatile support mode is significantly higher than that under constant speed mode (0.955Pa vs. 0.675Pa). Similarly, the OSI value under pulsatile mode is higher than that under constant speed mode (0.104 vs. 0.057). In addition, Ha under pulsatile mode for all selected cross-sections is larger than that under constant mode. Conclusions BJUT-II VAD, under pulsatile control mode, may prevent atherosclerosis lesions and aortic remodeling. The precise effects of pulsatile support mode on atherosclerosis and aortic remodeling need to be further studied in animal experiments. PMID:27363758

  7. Response Mode Effects on Computer Based Problem Solving.

    ERIC Educational Resources Information Center

    Sustik, Joan M.; Brown, Bobby R.

    Assessments were made of the impact of various overt response modes on the problem-solving process. The Luchins Water Jar Problems were presented to undergraduate university students via interactive cathode ray tube computer terminals under four response mode conditions: Mnemonic Code, Multiple Choice (MC), Numerical List, and Constructed Response…

  8. Effects of Fe(III) and organic matter additions on methanogenic activity and Fe(III) reduction in boreal lake and wetland sediments

    NASA Astrophysics Data System (ADS)

    Karvinen, Anu; Lehtinen, Lotta; Kankaala, Paula

    2013-04-01

    We studied potential methane production and Fe(III) reduction activity in lake sediments and wetland peat sampled from 14 sites in southern and eastern Finland. The concentration of total iron in the sediments and peat varied between 0.5 and 1200 ppm and their organic matter content (loss of ignition) varied between 1-98% of dry weight. Also the effects of added amorphous Fe(III) oxyhydroxide and organic matter (ammoniumacetate and/or sodiumacetate) on methanogenic and Fe(III) reduction activities were studied in anaerobic laboratory incubations (in vitro) lasting 5-20 days at 15 °C in darkness. Potential methane production and the effects of iron and acetate additions were highly variable between lake and peatland sites. The highest methanogenic potential was generally measured in productive littoral sites, especially in those dominated by Phragmites australis vegetation stands. In these sediments the total iron concentrations were high and acetate additions clearly increased methane production whereas Fe(III) additions decreased it. Our results demonstrate that microbial Fe(III) reduction plays an important role in the anaerobic organic matter decomposition in many boreal lakes.

  9. Computer Communication Modes and Their Effect on Student Attitudes Towards Programming.

    ERIC Educational Resources Information Center

    Boillot, Michel

    The effect of different communicating modes to computers on students' attitudes toward programing was studied. In a computer-related course, 13 students used batch processing mode to solve problems on the computer, while 12 other students used conversational mode to solve the same problems. It was found that those students accessing the computer…

  10. No Middle Ground, but Many Mansions: Design Features of Effective Mixed Mode Courses

    ERIC Educational Resources Information Center

    Pratt, D. D.

    2007-01-01

    In this account a model of communicative functions is used in an attempt to clarify the nature of mixed mode learning delivery. Formulated in research on communication in written mode, the model can be seen to offer insights into the nature of hypermedia communication, as well as helping to identify some key features of effective mixed mode course…

  11. Constructing an effective prevention mechanism for MSW lifecycle using failure mode and effects analysis.

    PubMed

    Chen, Ying-Chu; Wu, Wen-Fang

    2015-12-01

    Municipal solid waste in Taiwan is a valuable source of renewable energy. Phases of municipal solid waste lifecycle (classification, disposal, storage, collection and transportation) before incineration or landfilled face various potential failures. Applying a proper technique to eliminate or decrease potential failures is desirable and needed. Failure Modes and Effects Analysis to municipal solid waste lifecycle was found in literature. This study utilized the Failure Modes and Effects Analysis as a convenient technique for determining, classifying and analyzing common failures in the municipal solid waste lifecycle. As a result, an appropriate risk scoring of severity, occurrence, and detection of failure modes and computing the Risk Priority Number for identifying the high potential failure modes were made. Nineteen failure modes were identified, and nine of them were ranked as the priority items for improvement. Recommended actions for all failure modes were suggested. Occurrences of failures were remarkably reduced after implementing the procedure for six months. The results of this study have minimized potential failures and brought continuous improvement, thus achieving a better protection of the environment.

  12. Constructing an effective prevention mechanism for MSW lifecycle using failure mode and effects analysis.

    PubMed

    Chen, Ying-Chu; Wu, Wen-Fang

    2015-12-01

    Municipal solid waste in Taiwan is a valuable source of renewable energy. Phases of municipal solid waste lifecycle (classification, disposal, storage, collection and transportation) before incineration or landfilled face various potential failures. Applying a proper technique to eliminate or decrease potential failures is desirable and needed. Failure Modes and Effects Analysis to municipal solid waste lifecycle was found in literature. This study utilized the Failure Modes and Effects Analysis as a convenient technique for determining, classifying and analyzing common failures in the municipal solid waste lifecycle. As a result, an appropriate risk scoring of severity, occurrence, and detection of failure modes and computing the Risk Priority Number for identifying the high potential failure modes were made. Nineteen failure modes were identified, and nine of them were ranked as the priority items for improvement. Recommended actions for all failure modes were suggested. Occurrences of failures were remarkably reduced after implementing the procedure for six months. The results of this study have minimized potential failures and brought continuous improvement, thus achieving a better protection of the environment. PMID:26372404

  13. Coordination Modes in the Formation of Ternary Complexes of Am(III), Cm(III) and Eu(III) with EDTA and NTA: TRLFS, 13C NMR, EXAFS, and Thermodynamics of the complexation.

    SciTech Connect

    Mathur,J.; Thakur, P.; Dodge, C.; Francis, A.; Choppin, G.

    2006-01-01

    The formation and the structure of the ternary complexes of trivalent Am, Cm, and Eu with mixtures of EDTA+NTA (ethylenediamine tetraacetate and nitrilotriacetate) have been studied by time-resolved laser fluorescence spectroscopy, {sup 13}C NMR, extended X-ray absorption fine structure, and two-phase metal ion equilibrium distribution at 6.60 m (NaClO{sub 4}) and a hydrogen ion concentration value (pcH) between 3.60 and 11.50. In the ternary complexes, EDTA binds via four carboxylates and two nitrogens, while the binding of the NTA varies with the hydrogen ion concentration, pcH, and the concentration ratios of the metal ion and the ligand. When the concentration ratios of the metal to ligand is low (1:1:1-1:1:2), two ternary complexes, M(EDTA)(NTAH){sup 3-} and M(EDTA)(NTA){sup 4-}, are formed at pcH ca. 9.00 in which NTA binds via three carboxylates, via two carboxylates and one nitrogen, or via two carboxylates and a H{sub 2}O. At higher ratios (1:1:20 and 1:10:10) and pcH's of ca. 9.00 and 11.50, one ternary complex, M(EDTA)(NTA){sup 4-}, is formed in which NTA binds via three carboxylates and not via nitrogen. The two-phase equilibrium distribution studies at tracer concentrations of Am, Cm, and Eu have also confirmed the formation of the ternary complex M(EDTA)(NTA){sup 4-} at temperatures between 0 and 60 {sup o}C. The stability constants (log{beta}{sub 111}) for these metal ions increase with increasing temperature. The endothermic enthalpy and positive entropy indicated a significant effect of cation dehydration in the formation of the ternary complexes at high ionic strength.

  14. FMEA, the alternative process hazard method. [Failure Mode Effects Analysis

    SciTech Connect

    Goyal, R.K. )

    1993-05-01

    Failure mode effects analysis (FMEA) is an old reliability/assurance tool finding its way into the HPI. Not popular yet, this hazard technique has some viable applications that can improve hazard assessment data. Notably, FMEA studies can identify possible areas for improvement that may have not been discovered using other methods. Also, FMEA is not as labor intensive and costly as other process hazard analysis (PHA) methods. PSHA 1910.119 set in place an informational structure whose main purpose is the reduction of potential accidents and minimizing risks in the event of an accident. Consequently, HPI operators must evaluate their process systems and identify potential major hazards, such as fires, explosions and accidental release of toxic/hazardous chemicals, and protect their facilities, employees, the public and the environment. But, which PHA method(s) apply to a particular plant or process still remains a difficult question. This paper describes what FMEA is; types of FMEA; how to conduct a FMEA study; comparison with HAZOP (hazard and operability study); computer software; applicability of FMEA; and examples of its use.

  15. Inhibitory effects of indomethacin on growth and proliferation of gastric carcinoma cells KATO III.

    PubMed

    Fujiwara, Y; Tarnawski, A; Fujiwara, K; Arakawa, T; Kobayashi, K

    1993-06-01

    The effects of indomethacin on growth and proliferation of gastric carcinoma cells KATO III were examined. Indomethacin (10(-4) and 10(-3) M) significantly inhibited cell growth and these effects were not affected by treatment with 16,16-dimethyl prostaglandin E2 (3 x 10(-7) M and 3 x 10(-6) M). Indomethacin 10(-3) M significantly reduced cell viability and completely inhibited cell growth. Indomethacin 10(-4) M did not affect cell viability and its inhibitory effect of cell growth became apparent on the fifth day of culture. Indomethacin 10(-4) M reduced BrdU labeling index within 2 hours. These results suggest that indomethacin inhibited growth and proliferation of gastric carcinoma cells KATO III. This effect is not mediated by prostaglandins. PMID:8358051

  16. Collisionless microtearing modes in hot tokamaks: Effect of trapped electrons

    SciTech Connect

    Swamy, Aditya K.; Ganesh, R.; Brunner, S.; Vaclavik, J.; Villard, L.

    2015-07-15

    Collisionless microtearing modes have recently been found linearly unstable in sharp temperature gradient regions of large aspect ratio tokamaks. The magnetic drift resonance of passing electrons has been found to be sufficient to destabilise these modes above a threshold plasma β. A global gyrokinetic study, including both passing electrons as well as trapped electrons, shows that the non-adiabatic contribution of the trapped electrons provides a resonant destabilization, especially at large toroidal mode numbers, for a given aspect ratio. The global 2D mode structures show important changes to the destabilising electrostatic potential. The β threshold for the onset of the instability is found to be generally downshifted by the inclusion of trapped electrons. A scan in the aspect ratio of the tokamak configuration, from medium to large but finite values, clearly indicates a significant destabilizing contribution from trapped electrons at small aspect ratio, with a diminishing role at larger aspect ratios.

  17. The effect of magnetopause motion on fast mode resonance

    NASA Astrophysics Data System (ADS)

    Hartinger, M. D.; Welling, D.; Viall, N. M.; Moldwin, M. B.; Ridley, A.

    2014-10-01

    The Earth's magnetosphere supports several types of ultralow frequency (ULF) waves. These include fast mode resonance (FMR): cavity modes, waveguide modes, and tunneling modes/virtual resonance. The magnetopause, often treated as the outer boundary for cavity/waveguide modes in the dayside magnetosphere, is not stationary. A rapidly changing outer boundary condition—e.g., due to rapid magnetopause motion—is not favorable for FMR generation and may explain the sparseness of FMR observations in the outer magnetosphere. We examine how magnetopause motion affects the dayside magnetosphere's ability to sustain FMR with idealized Space Weather Modeling Framework (SWMF) simulations using the BATS-R-US global magnetohydrodynamic (MHD) code coupled with the Ridley Ionosphere Model (RIM). We present observations of FMR in BATS-R-US, reproducing results from other global MHD codes. We further show that FMR is present for a wide range of solar wind conditions, even during periods with large and rapid magnetopause displacements. We compare our simulation results to FMR observations in the dayside magnetosphere, finding that FMR occurrence does not depend on solar wind dynamic pressure, which can be used as a proxy for dynamic pressure fluctuations and magnetopause perturbations. Our results demonstrate that other explanations besides a nonstationary magnetopause—such as the inability to detect FMR in the presence of other ULF wave modes with large amplitudes—are required to explain the rarity of FMR observations in the outer magnetosphere.

  18. Influence of retrieval mode on effects of production: Evidence for costs in free recall.

    PubMed

    Mama, Yaniv; Icht, Michal

    2016-06-01

    Study modality (visual, auditory) of words as well as production mode (reading aloud, writing down) have been shown to influence the production effect (PE). When study words are presented visually, reading them aloud yields superior memory. However, when the same study words are presented aurally, writing them down leads to superior memory. Missing in PE studies is the variable of retrieval mode (written, aloud), which was addressed in the present study. In a pair of experiments, we manipulated the 3 variables-study modality, production mode, and retrieval mode-in a factorial fashion. With visual study, aloud production mode (vocalizing) was found to be superior to written production, in both retrieval modes (written and aloud). However, the difference between the productions was significantly smaller in the aloud retrieval mode relative to the written retrieval mode. With auditory study, written production mode was superior to aloud production mode, in the written as well as in the aloud retrieval modes. Here, the difference between the productions was significantly smaller in the written relative to the aloud retrieval mode. In other words, the difference between productions was smaller for the retrieval mode that matched the superior production. We interpret these findings using a retrieval-cost account. (PsycINFO Database Record PMID:27244359

  19. Influence of retrieval mode on effects of production: Evidence for costs in free recall.

    PubMed

    Mama, Yaniv; Icht, Michal

    2016-06-01

    Study modality (visual, auditory) of words as well as production mode (reading aloud, writing down) have been shown to influence the production effect (PE). When study words are presented visually, reading them aloud yields superior memory. However, when the same study words are presented aurally, writing them down leads to superior memory. Missing in PE studies is the variable of retrieval mode (written, aloud), which was addressed in the present study. In a pair of experiments, we manipulated the 3 variables-study modality, production mode, and retrieval mode-in a factorial fashion. With visual study, aloud production mode (vocalizing) was found to be superior to written production, in both retrieval modes (written and aloud). However, the difference between the productions was significantly smaller in the aloud retrieval mode relative to the written retrieval mode. With auditory study, written production mode was superior to aloud production mode, in the written as well as in the aloud retrieval modes. Here, the difference between the productions was significantly smaller in the written relative to the aloud retrieval mode. In other words, the difference between productions was smaller for the retrieval mode that matched the superior production. We interpret these findings using a retrieval-cost account. (PsycINFO Database Record

  20. Mixed-mode fracture of ceramics

    SciTech Connect

    Petrovic, J.J.

    1985-01-01

    The mixed-mode fracture behavior of ceramic materials is of importance for monolithic ceramics in order to predict the onset of fracture under generalized loading conditions and for ceramic composites to describe crack deflection toughening mechanisms. Experimental data on surface flaw mixed-mode fracture in various ceramics indicate that the flaw-plane normal stress at fracture decreases with increasing in-flaw-plane shear stress, although present data exhibit a fairly wide range in details of this sigma - tau relationship. Fracture from large cracks suggests that Mode II has a greater effect on Mode I fracture than Mode III. A comparison of surface flaw and large crack mixed-mode I-II fracture responses indicated that surface flaw behavior is influenced by shear resistance effects.

  1. Strain-effect transistors: Theoretical study on the effects of external strain on III-nitride high-electron-mobility transistors on flexible substrates

    SciTech Connect

    Shervin, Shahab; Asadirad, Mojtaba; Kim, Seung-Hwan; Ravipati, Srikanth; Lee, Keon-Hwa; Bulashevich, Kirill; Ryou, Jae-Hyun

    2015-11-09

    This paper presents strain-effect transistors (SETs) based on flexible III-nitride high-electron-mobility transistors (HEMTs) through theoretical calculations. We show that the electronic band structures of InAlGaN/GaN thin-film heterostructures on flexible substrates can be modified by external bending with a high degree of freedom using polarization properties of the polar semiconductor materials. Transfer characteristics of the HEMT devices, including threshold voltage and transconductance, are controlled by varied external strain. Equilibrium 2-dimensional electron gas (2DEG) is enhanced with applied tensile strain by bending the flexible structure with the concave-side down (bend-down condition). 2DEG density is reduced and eventually depleted with increasing compressive strain in bend-up conditions. The operation mode of different HEMT structures changes from depletion- to enchantment-mode or vice versa depending on the type and magnitude of external strain. The results suggest that the operation modes and transfer characteristics of HEMTs can be engineered with an optimum external bending strain applied in the device structure, which is expected to be beneficial for both radio frequency and switching applications. In addition, we show that drain currents of transistors based on flexible InAlGaN/GaN can be modulated only by external strain without applying electric field in the gate. The channel conductivity modulation that is obtained by only external strain proposes an extended functional device, gate-free SETs, which can be used in electro-mechanical applications.

  2. Magneto-optical effects in interacting localized and propagating surface plasmon modes.

    PubMed

    Torrado, Jorge F; González-Díaz, Juan B; González, María U; García-Martín, Antonio; Armelles, Gaspar

    2010-07-19

    We report that the effect of an external magnetic field on the propagation of surface plasmons can be effectively modified through the coupling between localized (LSP) and propagating (SPP) surface plasmons. When these plasmon modes do not interact, the main effect of the magnetic field is a modification of the wavevector of the SPP mode, leaving the LSP virtually unaffected. Once both modes start to interact, there is a strong variation of the magnetic field induced modification of the SPP dispersion curve and, simultaneously, the LSP mode becomes sensitive to the magnetic field.

  3. Effect of tris(3-hydroxy-4-pyridinonate) iron(III) complexes on iron uptake and storage in soybean (Glycine max L.).

    PubMed

    Santos, Carla S; Carvalho, Susana M P; Leite, Andreia; Moniz, Tânia; Roriz, Mariana; Rangel, António O S S; Rangel, Maria; Vasconcelos, Marta W

    2016-09-01

    Iron deficiency chlorosis (IDC) is a serious environmental problem affecting the growth of several crops in the world. The application of synthetic Fe(III) chelates is still one of the most common measures to correct IDC and the search for more effective Fe chelates remains an important issue. Herein, we propose a tris(3-hydroxy-4-pyridinonate) iron(III) complex, Fe(mpp)3, as an IDC corrector. Different morphological, biochemical and molecular parameters were assessed as a first step towards understanding its mode of action, compared with that of the commercial fertilizer FeEDDHA. Plants treated with the pyridinone iron(III) complexes were significantly greener and had increased biomass. The total Fe content was measured using ICP-OES and plants treated with pyridinone complexes accumulated about 50% more Fe than those treated with the commercial chelate. In particular, plants supplied with compound Fe(mpp)3 were able to translocate iron from the roots to the shoots and did not elicit the expression of the Fe-stress related genes FRO2 and IRT1. These results suggest that 3,4-HPO iron(III) chelates could be a potential new class of plant fertilizing agents.

  4. Effect of tris(3-hydroxy-4-pyridinonate) iron(III) complexes on iron uptake and storage in soybean (Glycine max L.).

    PubMed

    Santos, Carla S; Carvalho, Susana M P; Leite, Andreia; Moniz, Tânia; Roriz, Mariana; Rangel, António O S S; Rangel, Maria; Vasconcelos, Marta W

    2016-09-01

    Iron deficiency chlorosis (IDC) is a serious environmental problem affecting the growth of several crops in the world. The application of synthetic Fe(III) chelates is still one of the most common measures to correct IDC and the search for more effective Fe chelates remains an important issue. Herein, we propose a tris(3-hydroxy-4-pyridinonate) iron(III) complex, Fe(mpp)3, as an IDC corrector. Different morphological, biochemical and molecular parameters were assessed as a first step towards understanding its mode of action, compared with that of the commercial fertilizer FeEDDHA. Plants treated with the pyridinone iron(III) complexes were significantly greener and had increased biomass. The total Fe content was measured using ICP-OES and plants treated with pyridinone complexes accumulated about 50% more Fe than those treated with the commercial chelate. In particular, plants supplied with compound Fe(mpp)3 were able to translocate iron from the roots to the shoots and did not elicit the expression of the Fe-stress related genes FRO2 and IRT1. These results suggest that 3,4-HPO iron(III) chelates could be a potential new class of plant fertilizing agents. PMID:27156133

  5. Alpha-particle effects on ballooning flute modes in tokamaks

    SciTech Connect

    Andrushchenko, Z.N.; Bijko, A.Y.; Cheremnykh, O.K. )

    1990-11-01

    In this paper a more accurate dispersion equation for ideal ballooning flute modes in a plasma with alpha particles is obtained. It is shown that circulating and trapped alpha particles generate the eigenbranches of the mode oscillations with frequencies {omega} {approx lt} {omega}{sub *i}, where {omega}{sub *i}, is the ion drift frequency. The relevant growth rates and frequencies are found. It is ascertained that in the frequency range {omega}{sub *i} {lt} {omega} {lt} {bar {omega}{sub Db}}, where {bar {omega}{sub Db}} is the magnetic drift frequency average over a bounce period, trapped alpha particles may generate forced oscillations that influence the ideal ballooning flute mode stability boundary. It is shown that the stability may be improved for certain plasma parameters and trapped alpha-particle pressures.

  6. Quantum cascade emission in the III-nitride material system designed with effective interface grading

    SciTech Connect

    Song, Alex Y. Huang, Tzu-Yung; Zah, Chung-En; Gmachl, Claire F.; Bhat, Rajaram; Wang, Jie; Allerman, Andrew A.

    2015-09-28

    We report the realization of quantum cascade (QC) light emission in the III-nitride material system, designed with effective interface grading (EIG). EIG induces a continuous transition between wells and barriers in the quantum confinement, which alters the eigenstate system and even delocalizes the states with higher energy. Fully transverse-magnetic spontaneous emission is observed from the fabricated III-nitride QC structure, with a center wavelength of ∼4.9 μm and a full width at half maximum of ∼110 meV, both in excellent agreement with theoretical predictions. A multi-peak photo-response spectrum is also measured from the QC structure, which again agrees well with theoretical calculations and verifies the effects of EIG.

  7. EFFECTS OF A DEEP MIXED SHELL ON SOLAR g-MODES, p-MODES, AND NEUTRINO FLUX

    SciTech Connect

    Wolff, Charles L.

    2009-08-10

    A mixed-shell model that reflects g-modes away from the Sun's center is developed further by calibrating its parameters and evaluating a mixing mechanism: buoyancy. The shell roughly doubles g-mode oscillation periods and would explain why there is no definitive detection of their periods. But the shell has only minor effects on most p-modes. The model provides a mechanism for causing short-term fluctuations in neutrino flux and makes plausible the correlations between this flux and solar activity levels. Relations are derived for a shell heated asymmetrically by transient increases in nuclear burning in small 'hot spots'. The size of these spots and the timing of a heating event are governed by sets(l) of standing asymptotic g-modes, coupled by a maximal principle that greatly enhances their excitation and concentrates power toward the equator, assisting the detection of higher-l sets. Signals from all sets, except one, in the range 2 {<=} l {<=} 8 are identified by difference periods between consecutive radial states using the method of Garcia et al. and reinterpreting their latest spectrum. This confirms two detections of sets in a similar range of l by their rotation rates. The mean radius of shell mixing is r{sub m} = 0.16 R{sub sun}, which improves an earlier independent estimate of 0.18 by the author. The shell may cause the unexplained dip in measured sound speed at its location. Another sound speed error, centered near 0.67 R{sub sun}, and reversing flows in the same place with a period originally near 1.3 yr suggest that the g-modes are depositing there about 3% of the solar luminosity. That implies the shell at r{sub m} is receiving a similar magnitude of power, which would be enough energy to mix the corresponding shell in a standard solar model in <<10{sup 7} yr.

  8. Gd(III) complexes for electron-electron dipolar spectroscopy: Effects of deuteration, pH and zero field splitting

    NASA Astrophysics Data System (ADS)

    Garbuio, Luca; Zimmermann, Kaspar; Häussinger, Daniel; Yulikov, Maxim

    2015-10-01

    Spectral parameters of Gd(III) complexes are intimately linked to the performance of the Gd(III)-nitroxide or Gd(III)-Gd(III) double electron-electron resonance (DEER or PELDOR) techniques, as well as to that of relaxation induced dipolar modulation enhancement (RIDME) spectroscopy with Gd(III) ions. These techniques are of interest for applications in structural biology, since they can selectively detect site-to-site distances in biomolecules or biomolecular complexes in the nanometer range. Here we report relaxation properties, echo detected EPR spectra, as well as the magnitude of the echo reduction effect in Gd(III)-nitroxide DEER for a series of Gadolinium(III) complexes with chelating agents derived from tetraazacyclododecane. We observed that solvent deuteration does not only lengthen the relaxation times of Gd(III) centers but also weakens the DEER echo reduction effect. Both of these phenomena lead to an improved signal-to-noise ratios or, alternatively, longer accessible distance range in pulse EPR measurements. The presented data enrich the knowledge on paramagnetic Gd(III) chelate complexes in frozen solutions, and can help optimize the experimental conditions for most types of the pulse measurements of the electron-electron dipolar interactions.

  9. Coherence Effects of Caroli-de Gennes-Matricon Modes in Nodal Topological Superconductors

    NASA Astrophysics Data System (ADS)

    Tsutsumi, Yasumasa; Kato, Yusuke

    2016-05-01

    Coherence effects by the impurity scattering of Caroli-de Gennes-Matricon (CdGM) modes in a vortex for nodal topological superconductors have been studied. The coherence effects reflect a topological number defined on a particular momentum space avoiding the superconducting gap nodes. First, we analytically derived the eigenvalue and eigenfunction of the CdGM modes, including the zero-energy modes, in a nodal topological superconducting state without impurities, where we focused on a possible superconducting state of UPt3 as an example. Then, we studied impurity effects on the CdGM modes by introducing the impurity self-energy, which are dominated by the coherence factor depending on the eigenfunction of the CdGM modes. For the zero-energy CdGM modes, the coherence factor vanishes in a certain momentum range, which is guaranteed by topological invariance characterized by the one-dimensional winding number.

  10. Effects of chronic treatment with sodium tetrachloroaurate(III) in mice and membrane models.

    PubMed

    Suwalsky, Mario; Zambenedetti, Pamela; Carpené, Emilio; Ibnlkayat, Meryem; Wittkowski, Werner; Messori, Luigi; Zatta, Paolo

    2004-12-01

    Gold is a nonessential element with a variety of applications in medicine. A few gold(I) compounds are used in the clinics for treatment of rheumatoid arthritis and of discoid lupus. Some novel gold(III) compounds are under evaluation as anticancer agents. It is known that gold compounds generally produce toxic effects on the kidneys and characteristic lesions in the brain. However, information concerning the neurotoxicity of gold derivatives in humans as well as in experimental toxicology is rather scarce. For this reason we tried to shed some further light on this aspect of gold neurotoxicity by chronic treatment of mice with sodium tetrachloroaurate(III) in order to observe possible biophysical and morphological alterations that may occur in the brain. Chronic gold treatment resulted in a markedly decreased expression of metallothioneins and of glial fibrillary acidic protein in astrocytes of different brain areas. To examine its effects on cell membranes, interactions of sodium tetrachloroaurate(III) with molecular models were also evaluated. The models consisted in bilayers built-up of classes of phospholipids located in the outer and inner monolayers of biological membranes. Structural perturbation of cell membrane models was observed only at concentrations 10(5) times higher than those detected in the brains of animals after three months' treatment. These results show that toxic effects on animal brain upon treatment with sodium tetrachloroaurate develop with difficulty and may be observed only at high doses. PMID:15541497

  11. The effect of lanthanum(III) and cerium(III) ions between layers of manganese oxide on water oxidation.

    PubMed

    Najafpour, Mohammad Mahdi; Isaloo, Mohsen Abbasi; Hołyńska, Małgorzata; Shen, Jian-Ren; Allakhverdiev, Suleyman I; Allakhverdiev, Suleyman

    2015-12-01

    Manganese oxide structure with lanthanum(III) or cerium(III) ions between the layers was synthesized by a simple method. The ratio of Mn to Ce or La in samples was 0.00, 0.04, 0.08, 0.16, 0.32, 0.5, 0.82, or 1.62. The compounds were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction studies, and atomic absorption spectroscopy. The compounds show efficient catalytic activity of water oxidation in the presence of cerium(IV) ammonium nitrate with a turnover frequency of 1.6 mmol O2/mol Mn.s. In contrast to the water-oxidizing complex in Photosystem II, calcium(II) has no specific role to enhance the water-oxidizing activity of the layered manganese oxides and other cations can be replaced without any significant decrease in water-oxidizing activities of these layered Mn oxides. Based on this and previously reported results from oxygen evolution in the presence of H 2 (18) O, we discuss the mechanism and the important factors influencing the water-oxidizing activities of the manganese oxides. PMID:25701552

  12. Teacher Technology Literacy: Effects of Alternative Delivery Modes

    ERIC Educational Resources Information Center

    Tutty, Jeremy I.; Alfieri, Michele

    2009-01-01

    The task of preparing teachers to use technology in the classroom now extends beyond the walls of the university and into the classrooms of in-service teachers, as many states require technology competency for maintaining teaching credentials. In order to meet these needs, colleges and universities must seek alternative, but efficient modes for…

  13. The effect of reactor geometry on frontal polymerization spin modes

    NASA Astrophysics Data System (ADS)

    Pojman, John A.; Masere, Jonathan; Petretto, Enrico; Rustici, Mauro; Huh, Do-Sung; Kim, Min Suk; Volpert, Vladimir

    2002-03-01

    Using reactors of different sizes and geometries the dynamics of the frontal polymerization of 1,6-hexanediol diacrylate (HDDA) and pentaerythritol tetraacrylate (PETAC), with ammonium persulfate as the initiator were studied. For this system, the frontal polymerization exhibits complex behavior that depends on the ratio of the monomers. For a particular range of monomers concentration, the polymerization front becomes nonplanar, and spin modes appear. By varying the reactor diameter, we experimentally confirmed the expected shift of the system to a greater number of "hot spots" for larger diameters. For square test tubes a "zig-zag" mode was observed for the first time in frontal polymerization. We confirmed the viscosity-dependence of the spin mode instabilities. We also observed novel modes in cylinder-inside-cylinder reactors. Lastly, using a conical reactor with a continuously varying diameter, we observed what may be evidence for bistability depending on the direction of propagation. We discuss these finding in terms of the standard linear stability analysis for propagating fronts.

  14. 75 FR 11530 - Crystal Lake Wind III, LLC, et al.; Notice of Effectiveness of Exempt Wholesale Generator Status

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-11

    ... Energy Regulatory Commission Crystal Lake Wind III, LLC, et al.; Notice of Effectiveness of Exempt Wholesale Generator Status March 4, 2010. Docket Nos. Crystal Lake Wind III, LLC EG10-6-000 GardenGarden Wind, LLC EG10-7-000 Star Point Wind Project LLC EG10-8-000 Nacogdoches Power, LLC EG10-9-000...

  15. Failure mode and effects analysis outputs: are they valid?

    PubMed Central

    2012-01-01

    Background Failure Mode and Effects Analysis (FMEA) is a prospective risk assessment tool that has been widely used within the aerospace and automotive industries and has been utilised within healthcare since the early 1990s. The aim of this study was to explore the validity of FMEA outputs within a hospital setting in the United Kingdom. Methods Two multidisciplinary teams each conducted an FMEA for the use of vancomycin and gentamicin. Four different validity tests were conducted: · Face validity: by comparing the FMEA participants’ mapped processes with observational work. · Content validity: by presenting the FMEA findings to other healthcare professionals. · Criterion validity: by comparing the FMEA findings with data reported on the trust’s incident report database. · Construct validity: by exploring the relevant mathematical theories involved in calculating the FMEA risk priority number. Results Face validity was positive as the researcher documented the same processes of care as mapped by the FMEA participants. However, other healthcare professionals identified potential failures missed by the FMEA teams. Furthermore, the FMEA groups failed to include failures related to omitted doses; yet these were the failures most commonly reported in the trust’s incident database. Calculating the RPN by multiplying severity, probability and detectability scores was deemed invalid because it is based on calculations that breach the mathematical properties of the scales used. Conclusion There are significant methodological challenges in validating FMEA. It is a useful tool to aid multidisciplinary groups in mapping and understanding a process of care; however, the results of our study cast doubt on its validity. FMEA teams are likely to need different sources of information, besides their personal experience and knowledge, to identify potential failures. As for FMEA’s methodology for scoring failures, there were discrepancies between the teams’ estimates

  16. Effect of van der Waals interaction on the mode I fracture characteristics of graphene sheet

    NASA Astrophysics Data System (ADS)

    Parashar, Avinash; Mertiny, Pierre

    2013-11-01

    In this paper a study has been performed to investigate the effect of van der Waals interaction forces on the mode I (opening mode) fracture characteristics of a graphene sheet. Finite element based atomistic approach was employed to perform the investigation, where graphene structure was assumed to behave like a space frame structure. Few graphene sheets were modeled in finite element environment with different set of interlayer spacing. Modified virtual crack closure technique (VCCT) was employed to estimate the strain energy release rate (SERR) under mode I of fracture criteria. Significant effect of van der Waals forces was observed on the mode I fracture characteristics of graphene.

  17. Synthesis, enzymatic stability and in vitro cytostatic effect of Daunorubicin-GnRH-III derivative dimers.

    PubMed

    Schreier, Verena Natalie; Mező, Gábor; Orbán, Erika; Dürr, Claudia; Marquardt, Andreas; Manea, Marilena

    2013-04-01

    Bioconjugates containing chemotherapeutic agents attached to peptide hormones, such as gonadotropin-releasing hormone (GnRH), are developed as drug delivery systems for targeted cancer chemotherapy. We report here the synthesis and biochemical characterization of disulfide bond-linked dimeric bioconjugates in which daunorubicin was coupled via an oxime linkage to aminooxyacetylated GnRH-III ([Glp-His-Trp-Ser-His-Asp-Trp-Lys(DauAoa-Cys)-Pro-Gly-NH2]2; where Glp is pyroglutamic acid and Aoa is aminooxyacetyl) and its derivatives modified in position four by N-Me-Ser and Lys(Ac). The in vitro stability/degradation of the bioconjugates was determined in human serum, as well as in the presence of rat liver lysosomal homogenate and digestive enzymes. All compounds were stable at least for 24h in human serum and in the presence of pepsin and trypsin, while they were degraded by lysosomal enzymes. The daunorubicin-GnRH-III derivative dimers were partly digested by α-chymotrypsin; however, they had increased stability compared to the corresponding monomers, making them potential candidates for oral administration. The in vitro cytostatic effect of the compounds was determined on MCF-7 human breast cancer cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. All daunorubicin-GnRH-III derivative dimers exerted slightly increased in vitro cytostatic effect (IC50 values in low μM range) than the corresponding monomeric bioconjugates.

  18. Kinetic Differences and Synergistic Antiviral Effects Between Type I and Type III Interferon Signaling Indicate Pathway Independence

    PubMed Central

    Voigt, Emily A.

    2015-01-01

    The spread of acute respiratory viral infections is controlled by type I and III interferon (IFN) signaling. While the mechanisms of type I IFN signaling have been studied in detail, features that distinguish type III IFN signaling remain poorly understood. Type III IFNs play an essential role in limiting infections of intestinal and respiratory epithelial surfaces; however, type III IFNs have been shown to activate similar genes to type I IFNs, raising the question of how these IFNs differ and their signals interact. We measured the kinetics of type I and III IFN activation, functional stability, and downstream antiviral responses on A549 human lung epithelial cells. Similar kinetics were found for transcriptional upregulation and secretion of type I and III IFNs in response to infection by an RNA virus, peaking at 12 h postinfection, and both protein types had similar stabilities with functional half-lives extending beyond 2 days. Both IFNs activated potent cellular antiviral responses; however, responses to type III IFNs were delayed by 2–6 h relative to type I IFN responses. Combined treatments with type I and III IFNs produced enhanced antiviral effects, and quantitative analysis of these data with a Bliss interaction model provides evidence for independence of type I and III IFN downstream signaling pathways. This novel synergistic interaction has therapeutic implications for treatment of respiratory virus infections. PMID:25938799

  19. Anion Effects on Lanthanide(III) Tetrazole-1-acetate Dinuclear Complexes Showing Slow Magnetic Relaxation and Photofluorescent Emission.

    PubMed

    Lu, Ying-Bing; Jiang, Xiao-Ming; Zhu, Shui-Dong; Du, Zi-Yi; Liu, Cai-Ming; Xie, Yong-Rong; Liu, Liang-Xian

    2016-04-18

    Three types of lanthanide complexes based on the tetrazole-1-acetic acid ligand and the 2,2'-bipyridine coligand were prepared and characterized by single-crystal X-ray diffraction, IR spectroscopy, and elemental analyses; the formulas of these complexes are [Ln2(1-tza)4(NO3)2(2,2'-bipy)2] (Ln = Sm (1), Eu (2), Gd (3), Tb (4), Dy (5)), [Dy2(1-tza)4Cl2(2,2'-bipy)2] (6), and [Yb2(1-tza)4(NO3)2(2,2'-bipy)2] (7) (1-tza = tetrazole-1-acetate and 2,2'-bipy = 2,2'-bipyridine). They are dinuclear complexes possessing similar structures but different lanthanide(III) ion coordination geometries because of the distinction of peripheral anions (such as NO3(-) and Cl(-)) and the effect of lanthanide contraction. The variable-temperature magnetic susceptibilities of 1-6 were measured. Both Dy(III) complexes (5 and 6) display field-induced single-molecule magnet behaviors. Ab initio calculations revealed that the Dy(III) complex 6 possesses a more anisotropic Dy(III) ion in comparison to that in 5. The room-temperature photoluminescence spectra of Sm(III) (1), Eu(III) (2), Tb(III) (4), and Dy(III) (5 and 6) complexes exhibit strong characteristic emissions in the visible region, whereas the Yb(III) (7) complex shows near-infrared (NIR) luminescence. PMID:27023680

  20. Effect of Deformation Mode on the Wear Behavior of NiTi Shape Memory Alloys

    NASA Astrophysics Data System (ADS)

    Yan, Lina; Liu, Yong

    2016-06-01

    Owing to good biocompatibility, good fatigue resistance, and excellent superelasticity, various types of bio-medical devices based on NiTi shape memory alloy (SMA) have been developed. Due to the complexity in deformation mode in service, for example NiTi implants, accurate assessment/prediction of the surface wear process is difficult. This study aims at providing a further insight into the effect of deformation mode on the wear behavior of NiTi SMA. In the present study, two types of wear testing modes were used, namely sliding wear mode and reciprocating wear mode, to investigate the effect of deformation mode on the wear behavior of NiTi SMA in both martensitic and austenitic states. It was found that, when in martensitic state and under high applied loads, sliding wear mode resulted in more surface damage as compared to that under reciprocating wear mode. When in austenitic state, although similar trends in the coefficient of friction were observed, the coefficient of friction and surface damage in general is less under reciprocating mode than under sliding mode. These observations were further discussed in terms of different deformation mechanisms involved in the wear tests, in particular, the reversibility of martensite variant reorientation and stress-induced phase transformation, respectively.

  1. Effects of Spatial Variations in Coronal Temperatures on Type III Bursts. I. Variations in Electron Temperature

    NASA Astrophysics Data System (ADS)

    Li, B.; Cairns, Iver H.; Robinson, P. A.

    2011-03-01

    The electron temperature Te and ion temperature Ti in the corona vary with time and location, due to transient and persistent activity on the Sun. A method is developed for incorporating spatial variations of coronal temperatures into our previous simulation model for coronal type III bursts. The effects on type III bursts are simulated here for monotonic Te variations and/or for spatially localized disturbances in Te . Localized Te disturbances are found to have stronger effects than monotonic variations. In the presence of localized Te disturbances, the dynamic spectra of fp and 2fp emission are modulated at frequencies corresponding to the disturbances, showing intense fine structures that are narrow band and slowly drifting. The fp emission may be observable although still significantly weaker and more patchy than the 2fp emission. Distinct signatures of Te disturbances are found in the dependence on frequency of the 2fp spectral characteristics, e.g., the maximum flux. In the presence of monotonically varying Te , the frequency drift rate for 2fp emission agrees quantitatively with an extended version of the standard prediction, depending on the plasma density profile and a characteristic, non-constant beam speed, which varies with position via dependence on Te , and agrees quantitatively with the simulated beam dynamics. The results thus indicate that nonthermal type III bursts offer a new tool to probe both spatially localized Te structures and monotonic Te variations in the corona. The presence of localized Te disturbances may be responsible for some fine structures in type IIIs, e.g., the flux modulations in type IIIb bursts.

  2. Effect of confinement on the mode dynamics of dipole clusters.

    PubMed

    Schella, André; Melzer, André; July, Christoph; Bechinger, Clemens

    2015-02-14

    Dynamical properties of colloidal clusters composed of paramagnetic beads are presented. The clusters were trapped either in a parabolic trough or in a hard-wall confinement. In order to access the dynamics of the ensembles, the instantaneous normal mode (INM) approach is utilized, which uses cluster configurations as an input. The peaks in the mode spectra weaken when the system size is increased and when the coupling strength is lowered. The short-time diffusive properties of the clusters are deduced using the INM technique. It is found that angular diffusion is always larger than radial diffusion regardless of the shape of the external trap. Further, short-time diffusion seems to be almost independent of the coupling strength in the solid regime, but decreases with increasing packing fraction and size of the ensembles. In general, it is found that diffusion is larger for parabolically confined than for hard-wall trapped clusters.

  3. Effect of isotope mass on transport simulations of Joint European Torus high-mode plasmas with Edge Localized Modes

    NASA Astrophysics Data System (ADS)

    Bateman, Glenn; Kritz, Arnold H.; Parail, Vassili V.; Cordey, J. G.

    1999-12-01

    The effect of isotopic mass on heat and particle transport in Joint European Torus (JET) [P.-H. Rebut et al., Nucl. Fusion 25, 1011 (1985)] plasma discharges is studied using the Multi-Mode model in the BALDUR predictive transport code [Bateman et al., Phys. Plasmas 5, 1793 (1998)]. Temperature and density profiles from these simulations generally agree with the experimentally measured profiles for high-mode JET discharges with Edge Localized Modes in hydrogen, deuterium, and tritium discharges. It is surprising that a purely gyro-Bohm transport model, used in these simulations, correctly predicts the experimentally observed improvement in confinement as the isotope mass is increased—given the fact that gyro-Bohm diffusion coefficients increase with isotope mass when the shapes of all the plasma profiles are held fixed. However, in the JET experiment, it was found that the electron and ion temperature at the top of the edge pedestal increases systematically as the isotope mass in increased (J. G. Cordey et al., Report No. JET-P (98)53, 1998). The numerical simulations reported here show that this increase in the edge temperatures and subsequent broadening of the temperature profiles account for the improvement in confinement as the isotope mass is increased.

  4. Effects of light curing modes and ethanol-wet bonding on dentin bonding properties*

    PubMed Central

    Li, Mu-zi; Wang, Jin-rui; Liu, Hong; Wang, Xia; Gan, Kang; Liu, Xiu-ju; Niu, De-li; Song, Xiao-qing

    2016-01-01

    Objective: This study explored the effects of different light curing modes and ethanol-wet bonding on dentin bonding strength and durability. Methods: A total of 54 molars were randomly divided into three groups: Single Bond 2, Gluma Comfort Bond, and N-Bond. Based on the three light-curing modes and presence or absence of ethanol pretreatment, the samples were assigned to six subgroups: high-light mode, ethanol pretreatment+high-light mode, soft-start mode, ethanol pretreatment+soft-start mode, standard mode, and ethanol pretreatment+standard mode. All samples were bonded with resin based on the experimental groups. After 24 h and 6 months of water storage, a universal testing machine was used to measure microtensile bond strength. Scanning electron microscopy (SEM) was applied to observe mixed layer morphology. Results: The 24-h and 6-month microtensile bond strengths of the ethanol pretreatment groups were significantly higher than those of the non-ethanol pretreatment groups at the same light modes (P<0.05). With or without ethanol pretreatment, the microtensile bond strengths of the high-light modes were significantly lower than those of the soft-start modes and standard modes (P<0.05). The microtensile bond strengths of samples from the 6-month water storage group significantly decreased compared with those of samples from the 24-h water storage group (P<0.05). The soft-start groups and standard groups formed better mixed layers than the high-light mode groups, whereas the ethanol pretreatment groups formed more uniform mixed layers than those without ethanol pretreatment. Conclusions: Ethanol-wet bonding technique, soft-start, and standard modes could improve dentin bonding properties. PMID:27604862

  5. The gallium(III)-salicylidene acylhydrazide complex shows synergistic anti-biofilm effect and inhibits toxin production by Pseudomonas aeruginosa.

    PubMed

    Rzhepishevska, Olena; Hakobyan, Shoghik; Ekstrand-Hammarström, Barbro; Nygren, Yvonne; Karlsson, Torbjörn; Bucht, Anders; Elofsson, Mikael; Boily, Jean-François; Ramstedt, Madeleine

    2014-09-01

    Bacterial biofilms cause a range of problems in many areas and especially in health care. Biofilms are difficult to eradicate with traditional antibiotics and consequently there is a need for alternative ways to prevent and/or remove bacterial biofilms. Furthermore, the emergence of antibiotic resistance in bacteria creates a challenge to find new types of antibiotics with a lower evolutionary pressure for resistance development. One route to develop such drugs is to target the so called virulence factors, i.e. bacterial systems used when bacteria infect a host cell. This study investigates synergy effects between Ga(III) ions, previously reported to suppress biofilm formation and growth in bacteria, and salicylidene acylhydrazides (hydrazones) that have been proposed as antivirulence drugs targeting the type three secretion system used by several Gram-negative pathogens, including Pseudomonas aerugionosa, during bacterial infection of host cells. A library of hydrazones was screened for: Fe(III) binding, enhanced anti-biofilm effect with Ga(III) on P. aeruginosa, and low cytotoxicity to mammalian cells. The metal coordination for the most promising ligand, 2-Oxo-2-[N-(2,4,6-trihydroxy-benzylidene)-hydrazino]-acetamide (ME0163) with Ga(III) was investigated using extended X-ray absorption fine structure spectroscopy as well as density functional theory. The results showed that Ga(III) chelates the hydrazone with 5- and 6-membered chelating rings, and that the Ga(III)-ME0163 complex enhanced the antibiofilm effect of Ga(III) while suppressing the type three secretion system in P. aeruginosa. The latter effect was not observed for the hydrazone alone and was similar for Ga(III)-citrate and Ga(III)-ME0163 complexes, indicating that the inhibition of virulence was caused by Ga(III).

  6. Tricarboxylate-based Gd(III) coordination polymers exhibiting large magnetocaloric effects.

    PubMed

    Liu, Sui-Jun; Cao, Chen; Xie, Chen-Chao; Zheng, Teng-Fei; Tong, Xiao-Lan; Liao, Jin-Sheng; Chen, Jing-Lin; Wen, He-Rui; Chang, Ze; Bu, Xian-He

    2016-05-31

    Two Gd(III) coordination polymers with the formula [Gd(cit)(H2O)]∞ () and [Gd(nta)(H2O)2]∞ () (H4cit = citric acid, H3nta = nitrilotriacetic acid) have been successfully prepared under hydrothermal conditions. Complex exhibits a three-dimensional (3D) structure based on carboxylate-bridged layers, while complex is a double-layer structure containing eight-coordinated Gd(III). Magnetic investigations reveal that weak antiferromagnetic couplings between adjacent Gd(III) ions in both and with different Weiss values result in large cryogenic magnetocaloric effects. It is notable that the maximum entropy changes (-ΔS) of and reach 31.3 J kg(-1) K(-1) and 32.2 J kg(-1) K(-1) at 2 K for a moderate field change (ΔH = 3 T), and a remarkable -ΔS (41.5 J kg(-1) K(-1) for and 42.0 J kg(-1) K(-1) for ) could be obtained for ΔH = 7 T.

  7. Differential effects of Heparitinase I and Heparitinase III on endothelial tube formation in vitro

    PubMed Central

    Raman, Karthik; Kuberan, Balagurunathan

    2010-01-01

    Heparan sulfate proteoglycans (HSPGs) play vital roles in many steps of angiogenesis under physiological and pathological conditions. HSPGs on endothelial cell surfaces act as coreceptors for a variety of pro-angiogenic growth factors such as FGF and VEGF and anti-angiogenic factors such as endostatin. However, the fine structural requirements of these binding interactions are dependent on the sulfation patterns of HSPGs. Previous studies have shown that Heparitinases, heparin lyases isolated from flavobacterium heparinum, can cleave heparan sulfate chains. These enzymes have been shown to reduce tumor—derived neovascularization in vivo in mice. However, the results from these experiments could not conclusively pinpoint the origin of the HS fragments. Thus, in this study we utilized an in vitro assay to assess the differential effects of Heparitinase I (Hep I) and Heparitinase III (Hep III) on endothelial tube formation. Hep III was found to be a more potent inhibitor of tube formation than Hep I. In conclusion, differential cleavage of endothelial cell surface bound HS can affect the extent of inhibition of tube formation. PMID:20599743

  8. Resonance Raman effect in mu-oxo-bis[iron(III) tetraphenylporphyrin].

    PubMed Central

    Adar, F; Srivastava, T S

    1975-01-01

    Resonance Raman spectra of mu-oxo-bis[iron(III) tetraphenylporphyrin] have been observed and compared to Raman spectra of the monomers iron(III) tetraphenylporphyrin chloride and bis(piperidine)iron(II) tetraphenylporphyrin. Selection rules for the Raman effect under conditions of resonance of the incident photons with electronic states are presented for the exact symmetry group (C2) and the pseudo-symmetry group (D4d): emphasis is placed on the physical processes involved in scattering via vibronic states of the dimer. These two models are experimentally distinguishable in the behavior of the depolarization ratios of the dimer vibrational doublets. Experimental data favor the assignment of D4d as the symmetry group relevant to a description of the various states of the dimer. The usefulness of resonance Raman spectra of the mu-oco-dimer of Fe(III) tetraphenylporphyrin has been discussed with respect to several biochemical systems where there is strong evidence of two or more closely interacting chromophores. PMID:1060121

  9. The Effect of Plasma Shape on H-Mode Pedestal Characteristics on DIII-D

    SciTech Connect

    T.H. Osborne; J.R. Ferron; R.J. Groebner; L.L. Lao; A.W. Leonard; R. Maingi; R.L. Miller; A.D. Turnbull; M.R. Wade; J.G. Watkins

    1999-12-01

    The characteristics of the H-mode are studied in discharges with varying triangularity and squareness. The pressure at the top of the H-mode pedestal increases strongly with triangularity primarily due to an increase in the margin by which the edge pressure gradient exceeds the ideal ballooning mode first stability limit. Two models are considered for how the edge may exceed the ballooning mode limit. In one model [1], access to the ballooning mode second stable regime allows the edge pressure gradient and associated bootstrap current to continue to increase until an edge localized, low toroidal mode number, ideal kink mode is destabilized. In the second model [2], the finite width of the H-mode transport barrier, and diamagnetic effects raise the pressure gradient limit above the ballooning mode limit. We observe a weak inverse dependence of the width of the H-mode transport barrier, {Delta}, on triangularity relative to the previously obtained [3] scaling {Delta} {infinity} ({beta}{sub P}{sup PED}){sup 1/2}. The energy loss for Type I ELMs increases with triangularity in proportion to the pedestal energy increase. The temperature profile is found to respond stiffly to changes in T{sup PED} at low temperature, while at high temperature the response is additive. The response of the density profile is also found to play a role in the response of the total stored energy to changes in the W{sup PED}.

  10. The genome of an Encephalitozoon cuniculi type III strain reveals insights into the genetic diversity and mode of reproduction of a ubiquitous vertebrate pathogen.

    PubMed

    Pelin, A; Moteshareie, H; Sak, B; Selman, M; Naor, A; Eyahpaise, M-È; Farinelli, L; Golshani, A; Kvac, M; Corradi, N

    2016-05-01

    Encephalitozoon cuniculi is a model microsporidian species with a mononucleate nucleus and a genome that has been extensively studied. To date, analyses of genome diversity have revealed the existence of four genotypes in E. cuniculi (EcI, II, III and IV). Genome sequences are available for EcI, II and III, and are all very divergent, possibly diploid and genetically homogeneous. The mechanisms that cause low genetic diversity in E. cuniculi (for example, selfing, inbreeding or a combination of both), as well as the degree of genetic variation in their natural populations, have been hard to assess because genome data have been so far gathered from laboratory-propagated strains. In this study, we aim to tackle this issue by analyzing the complete genome sequence of a natural strain of E. cuniculi isolated in 2013 from a steppe lemming. The strain belongs to the EcIII genotype and has been designated EcIII-L. The EcIII-L genome sequence harbors genomic features intermediate to known genomes of II and III lab strains, and we provide primers that differentiate the three E. cuniculi genotypes using a single PCR. Surprisingly, the EcIII-L genome is also highly homogeneous, harbors signatures of heterozygosity and also one strain-specific single-nucleotide polymorphism (SNP) that introduces a stop codon in a key meiosis gene, Spo11. Functional analyses using a heterologous system demonstrate that this SNP leads to a deficient meiosis in a model fungus. This indicates that EcIII-L meiotic machinery may be presently broken. Overall, our findings reveal previously unsuspected genome diversity in E. cuniculi, some of which appears to affect genes of primary importance for the biology of this pathogen.

  11. The genome of an Encephalitozoon cuniculi type III strain reveals insights into the genetic diversity and mode of reproduction of a ubiquitous vertebrate pathogen.

    PubMed

    Pelin, A; Moteshareie, H; Sak, B; Selman, M; Naor, A; Eyahpaise, M-È; Farinelli, L; Golshani, A; Kvac, M; Corradi, N

    2016-05-01

    Encephalitozoon cuniculi is a model microsporidian species with a mononucleate nucleus and a genome that has been extensively studied. To date, analyses of genome diversity have revealed the existence of four genotypes in E. cuniculi (EcI, II, III and IV). Genome sequences are available for EcI, II and III, and are all very divergent, possibly diploid and genetically homogeneous. The mechanisms that cause low genetic diversity in E. cuniculi (for example, selfing, inbreeding or a combination of both), as well as the degree of genetic variation in their natural populations, have been hard to assess because genome data have been so far gathered from laboratory-propagated strains. In this study, we aim to tackle this issue by analyzing the complete genome sequence of a natural strain of E. cuniculi isolated in 2013 from a steppe lemming. The strain belongs to the EcIII genotype and has been designated EcIII-L. The EcIII-L genome sequence harbors genomic features intermediate to known genomes of II and III lab strains, and we provide primers that differentiate the three E. cuniculi genotypes using a single PCR. Surprisingly, the EcIII-L genome is also highly homogeneous, harbors signatures of heterozygosity and also one strain-specific single-nucleotide polymorphism (SNP) that introduces a stop codon in a key meiosis gene, Spo11. Functional analyses using a heterologous system demonstrate that this SNP leads to a deficient meiosis in a model fungus. This indicates that EcIII-L meiotic machinery may be presently broken. Overall, our findings reveal previously unsuspected genome diversity in E. cuniculi, some of which appears to affect genes of primary importance for the biology of this pathogen. PMID:26837273

  12. Finite Larmor radius effects on the (m = 2, n = 1) cylindrical tearing mode

    NASA Astrophysics Data System (ADS)

    Chen, Y.; Chowdhury, J.; Parker, S. E.; Wan, W.

    2015-04-01

    New field solvers are developed in the gyrokinetic code GEM [Chen and Parker, J. Comput. Phys. 220, 839 (2007)] to simulate low-n modes. A novel discretization is developed for the ion polarization term in the gyrokinetic vorticity equation. An eigenmode analysis with finite Larmor radius effects is developed to study the linear resistive tearing mode. The mode growth rate is shown to scale with resistivity as γ ˜ η1/3, the same as the semi-collisional regime in previous kinetic treatments [Drake and Lee, Phys. Fluids 20, 1341 (1977)]. Tearing mode simulations with gyrokinetic ions are verified with the eigenmode calculation.

  13. A study of the relative effectiveness and cost of computerized information retrieval in the interactive mode

    NASA Technical Reports Server (NTRS)

    Smetana, F. O.; Furniss, M. A.; Potter, T. R.

    1974-01-01

    Results of a number of experiments to illuminate the relative effectiveness and costs of computerized information retrieval in the interactive mode are reported. It was found that for equal time spent in preparing the search strategy, the batch and interactive modes gave approximately equal recall and relevance. The interactive mode however encourages the searcher to devote more time to the task and therefore usually yields improved output. Engineering costs as a result are higher in this mode. Estimates of associated hardware costs also indicate that operation in this mode is more expensive. Skilled RECON users like the rapid feedback and additional features offered by this mode if they are not constrained by considerations of cost.

  14. Effect of toroidal magnetic field on n = 1 mode stability in rotamak plasmas

    SciTech Connect

    Yang, X.; Goss, J.; Kalaria, D.; Huang, T. S.

    2011-08-15

    To study the effect of toroidal magnetic field on n = 1 mode stability, a series of experiments with linearly ramping the axial current I{sub z}, which makes field-reversed configuration (FRC) to spherical tokamak (ST) transition, have been conducted in rotamak. Results clearly demonstrate that the tilt mode can be completely suppressed by small I{sub z} around 0.4 kA (in comparison with 2.0 kA plasma current). An unknown new mode with larger magnetic perturbations is triggered when I{sub z} reaches 0.5 kA. This instability mode keeps saturation while plasma current is boosted when I{sub z} is in the range of 0.6-1.4 kA. When I{sub z} exceeds 1.6 kA, the new mode suddenly disappears and discharge is free from instability modes.

  15. Curvature effect on tearing modes in presence of neoclassical friction

    NASA Astrophysics Data System (ADS)

    Maget, Patrick; Mellet, Nicolas; Lütjens, Hinrich; Meshcheriakov, Dmytro; Garbet, Xavier

    2013-11-01

    Neoclassical physics (here associated to the poloidal variation of the magnetic field strength along field lines in a tokamak) is well known for driving self-generated plasma current and nonlinear magnetic islands associated to it in high performance, ITER relevant plasma discharges. It is demonstrated that the neoclassical friction between a magnetic perturbation and plasma flow already impacts magnetic islands in the linear regime, by inducing a weakening of curvature stabilization for tearing modes. This conclusion holds in particular for regimes where convection is influencing the pressure dynamics, as shown using a simple analytical model and confirmed in full Magneto-Hydro-Dynamics simulations.

  16. Curvature effect on tearing modes in presence of neoclassical friction

    SciTech Connect

    Maget, Patrick; Mellet, Nicolas; Meshcheriakov, Dmytro; Garbet, Xavier; Lütjens, Hinrich

    2013-11-15

    Neoclassical physics (here associated to the poloidal variation of the magnetic field strength along field lines in a tokamak) is well known for driving self-generated plasma current and nonlinear magnetic islands associated to it in high performance, ITER relevant plasma discharges. It is demonstrated that the neoclassical friction between a magnetic perturbation and plasma flow already impacts magnetic islands in the linear regime, by inducing a weakening of curvature stabilization for tearing modes. This conclusion holds in particular for regimes where convection is influencing the pressure dynamics, as shown using a simple analytical model and confirmed in full Magneto-Hydro-Dynamics simulations.

  17. Recall of Brief Television News Items: Effects of Presentation Mode, Picture Content and Serial Position.

    ERIC Educational Resources Information Center

    Gunter, B.

    1979-01-01

    An experiment was conducted to examine the effects of presentation mode, picture content, and serial position upon the recall of brief television news items. Fifteen items were presented in either video- or audio-only mode to 40 subjects. The results are discussed in terms of various imagery hypotheses. (Author)

  18. Effects of the Coriolis force on high-order g modes in γ Doradus stars

    NASA Astrophysics Data System (ADS)

    Bouabid, M.-P.; Dupret, M.-A.; Salmon, S.; Montalbán, J.; Miglio, A.; Noels, A.

    2013-03-01

    γ Doradus stars pulsate with high-order gravity modes having typical frequencies which can be comparable to or higher than their rotation frequencies. Therefore, rotation has a non-negligible effect on their oscillation properties. To explore the rotation-pulsation coupling in γ Dor stars, we perform a non-adiabatic study including the traditional approximation of rotation on a grid of spherical stellar models covering the mass range 1.4 < M* < 2.1 M⊙. This approximation allows us to treat the effect of the Coriolis force on the frequencies and the stability of high-order g modes. The effect of the Coriolis force depends on the kind of mode considered (prograde sectoral or not) and increases with their periods. As a consequence, we first find that the period spacing between modes is no longer periodically oscillating around a constant value. Secondly, we show that the frequency gap (5-15 cycles day-1) arising from stable modes between γ Dor-type high-order g modes and δ Scuti-type modes can be easily filled by g-mode frequencies shifted to higher values by the rotation. Thirdly, we analyse the combined effect of diffusive mixing and the Coriolis force on the period spacings. And finally, we predict a slight broadening of the γ Dor instability strip.

  19. Overview of the effect of Title III of the 1990 Clean Air Act Amendments on the natural gas industry

    SciTech Connect

    Child, C.J.

    1995-12-31

    The regulation of hazardous air pollutants by Title III of the Clean Air Act Amendments of 1990 has a potential wide-ranging impact for the natural gas industry. Title III includes a list of 189 hazardous air pollutants (HAPs) which are targeted for reduction. Under Title III, HAP emissions from major sources will be reduced by the implementation of maximum achievable control technology (MACT) standards. If the source is defined as a major source, it must also comply with Title V (operating permit) and Title VII (enhanced monitoring) requirements. This presentation will review Title III`s effect on the natural gas industry by discussing the regulatory requirements and schedules associated with MACT as well as the control technology options available for affected sources.

  20. Combined effects of Lanthanum(III) and elevated Ultraviolet-B radiation on root nitrogen nutrient in soybean seedlings.

    PubMed

    Huang, Guangrong; Wang, Lihong; Sun, Zhaoguo; Li, Xiaodong; Zhou, Qing; Huang, Xiaohua

    2015-02-01

    Rare earth element pollution and elevated ultraviolet-B (UV-B) radiation occur simultaneously in some regions, but the combined effects of these two factors on plants have not attracted enough attention. Nitrogen nutrient is vital to plant growth. In this study, the combined effects of lanthanum(III) and elevated UV-B radiation on nitrate reduction and ammonia assimilation in soybean (Glycine max L.) roots were investigated. Treatment with 0.08 mmol L(-1) La(III) did not change the effects of elevated UV-B radiation on nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS), glutamate synthase (GOGAT), glutamate dehydrogenase (GDH), nitrate, ammonium, amino acids, or soluble protein in the roots. Treatment with 0.24 mmol L(-1) La(III) and elevated UV-B radiation synergistically decreased the NR, NiR, GS, and GOGAT activities as well as the nitrate, amino acid, and soluble protein levels, except for the GDH activity and ammonium content. Combined treatment with 1.20 mmol L(-1) La(III) and elevated UV-B radiation produced severely deleterious effects on all test indices, and these effects were stronger than those induced by La(III) or elevated UV-B radiation treatment alone. Following the withdrawal of La(III) and elevated UV-B radiation, all test indices for the combined treatments with 0.08/0.24 mmol L(-1) La(III) and elevated UV-B radiation recovered to a certain extent, but they could not recover for treatments with 1.20 mmol L(-1) La(III) and elevated UV-B radiation. In summary, combined treatment with La(III) and elevated UV-B radiation seriously affected nitrogen nutrition in soybean roots through the inhibition of nitrate reduction and ammonia assimilation.

  1. Nitric oxide interacts with mitochondrial complex III producing antimycin-like effects.

    PubMed

    Iglesias, Darío E; Bombicino, Silvina S; Valdez, Laura B; Boveris, Alberto

    2015-12-01

    The effect of NO between cytochromes b and c of the mitochondrial respiratory chain were studied using submitochondrial particles (SMP) from bovine heart and GSNO and SPER-NO as NO sources. Succinate-cytochrome c reductase (complex II-III) activity (222 ± 4 nmol/min. mg protein) was inhibited by 51% in the presence of 500 μM GSNO and by 48% in the presence of 30 μM SPER-NO, in both cases at ~1.25 μM NO. Neither GSNO nor SPER-NO were able to inhibit succinate-Q reductase activity (complex II; 220 ± 9 nmol/min. mg protein), showing that NO affects complex III. Complex II-III activity was decreased (36%) when SMP were incubated with l-arginine and mtNOS cofactors, indicating that this effect is also produced by endogenous NO. GSNO (500 μM) reduced cytochrome b562 by 71%, in an [O2] independent manner. Hyperbolic increases in O2(•-) (up to 1.3 ± 0.1 nmol/min. mg protein) and H2O2 (up to 0.64 ± 0.05 nmol/min. mg protein) productions were observed with a maximal effect at 500 μM GSNO. The O2(•-)/H2O2 ratio was 1.98 in accordance with the stoichiometry of the O2(•-) disproportionation. Moreover, H2O2 production was increased by 72-74% when heart coupled mitochondria were exposed to 500 μM GSNO or 30 μM SPER-NO. SMP incubated in the presence of succinate showed an EPR signal (g=1.99) compatible with a stable semiquinone. This EPR signal was increased not only by antimycin but also by GSNO and SPER-NO. These signals were not modified under N2 atmosphere, indicating that they are not a consequence to the effect of NOx species on complex III area. These results show that NO interacts with ubiquinone-cytochrome b area producing antimycin-like effects. This behaviour comprises the inhibition of electron transfer, the interruption of the oxidation of cytochromes b, and the enhancement of [UQH(•)]ss which, in turn, leads to an increase in O2(•-) and H2O2 mitochondrial production rates. PMID:26456055

  2. Nitric oxide interacts with mitochondrial complex III producing antimycin-like effects.

    PubMed

    Iglesias, Darío E; Bombicino, Silvina S; Valdez, Laura B; Boveris, Alberto

    2015-12-01

    The effect of NO between cytochromes b and c of the mitochondrial respiratory chain were studied using submitochondrial particles (SMP) from bovine heart and GSNO and SPER-NO as NO sources. Succinate-cytochrome c reductase (complex II-III) activity (222 ± 4 nmol/min. mg protein) was inhibited by 51% in the presence of 500 μM GSNO and by 48% in the presence of 30 μM SPER-NO, in both cases at ~1.25 μM NO. Neither GSNO nor SPER-NO were able to inhibit succinate-Q reductase activity (complex II; 220 ± 9 nmol/min. mg protein), showing that NO affects complex III. Complex II-III activity was decreased (36%) when SMP were incubated with l-arginine and mtNOS cofactors, indicating that this effect is also produced by endogenous NO. GSNO (500 μM) reduced cytochrome b562 by 71%, in an [O2] independent manner. Hyperbolic increases in O2(•-) (up to 1.3 ± 0.1 nmol/min. mg protein) and H2O2 (up to 0.64 ± 0.05 nmol/min. mg protein) productions were observed with a maximal effect at 500 μM GSNO. The O2(•-)/H2O2 ratio was 1.98 in accordance with the stoichiometry of the O2(•-) disproportionation. Moreover, H2O2 production was increased by 72-74% when heart coupled mitochondria were exposed to 500 μM GSNO or 30 μM SPER-NO. SMP incubated in the presence of succinate showed an EPR signal (g=1.99) compatible with a stable semiquinone. This EPR signal was increased not only by antimycin but also by GSNO and SPER-NO. These signals were not modified under N2 atmosphere, indicating that they are not a consequence to the effect of NOx species on complex III area. These results show that NO interacts with ubiquinone-cytochrome b area producing antimycin-like effects. This behaviour comprises the inhibition of electron transfer, the interruption of the oxidation of cytochromes b, and the enhancement of [UQH(•)]ss which, in turn, leads to an increase in O2(•-) and H2O2 mitochondrial production rates.

  3. Reduction of ethylenediaminetetraacetic acid iron(III) by Klebsiella sp. FD-3 immobilized on iron(II, III) oxide poly (styrene-glycidyl methacrylate) magnetic porous microspheres: effects of inorganic compounds and kinetic study of effective diffusion in porous media.

    PubMed

    Zhou, Zuo-Ming; Wang, Xiao-Yan; Lin, Tian-Ming; Jing, Guo-Hua

    2014-11-01

    Fe3O4 poly (styrene-glycidyl methacrylate) magnetic porous microspheres (MPPMs) were introduced to immobilize Klebsiella sp. FD-3, an iron-reducing bacterium applied to reduce Fe(III)EDTA. The effects of potential inhibitors (S(2-), SO3(2-), NO3(-), NO2(-) and Fe(II)EDTA-NO) on Fe(III)EDTA reduction were investigated. S(2-) reacted with Fe(III)EDTA as an electron-shuttling compound and enhanced the reduction. But Fe(III)EDTA reduction was inhibited by SO3(2-) and Fe(II)EDTA-NO due to their toxic to microorganisms. Low concentrations of NO3(-) and NO2(-) accelerated Fe(III)EDTA reduction, but high concentrations inhibited the reduction, whether by free or immobilized FD-3. The immobilized FD-3 performed better than freely-suspended style. The substrate mass transfer and diffusion kinetics in the porous microspheres were calculated. The value of Thiele modulus and effectiveness factors showed that the intraparticle diffusion was fairly small and neglected in this carrier. Fe(III)EDTA reduction fitted first-order model at low Fe(III)EDTA concentration, and changed to zero-order model at high concentrations.

  4. Effective Hamiltonians for Coriolis-coupled nearly degenerate modes: Illustrative examples

    NASA Astrophysics Data System (ADS)

    Krishnan, Mangala S.; Carrington, Tucker, Jr.

    1993-11-01

    Using an angular momentum dependent Bogoliubov-Tyablikov (BT) transformation technique effective rotational Hamiltonians are derived for four molecules all of which have a pair of nearly degenerate strongly coupled vibrational modes. The BT transformation is applied to a two-vibrational-mode Hamiltonian obtained by using perturbation theory to eliminate the coupling between all but the nearly degenerate modes. Energy levels computed from the BT effective rotational Hamiltonians and accurate variational calculations agree very well. BT effective Hamiltonians are derived and tested for ozone, formaldehyde, its singly deuterated analog, and chlorodifluoromethane.

  5. Effect of density gradients in confined supersonic shear layers. Part 2: 3-D modes

    NASA Technical Reports Server (NTRS)

    Peroomian, Oshin; Kelly, R. E.

    1994-01-01

    The effect of basic flow density gradients on the supersonic wall modes were investigated in Part 1 of this analysis. In that investigation only the 2-D modes were studied. Tam and Hu investigated the 3-D modes in a confined vortex sheet and reported that the first 2-D Class A mode (A01) had the highest growth rate compared to all other 2-D and 3-D modes present in the vortex sheet for that particular set of flow patterns. They also showed that this result also held true for finite thickness shear layers with delta(sub w) less than 0.125. For free shear layers, Sandham and Reynolds showed that the 3-D K-H mode became the dominant mode for M(sub c) greater than 0.6. Jackson and Grosch investigated the effect of crossflow and obliqueness on the slow and fast odes present in a M(sub c) greater than 1 environment and showed that for certain combination of crossflow and wave angles the growth rates could be increased by up to a factor of 2 with respect to the 2-D case. The case studied here is a confined shear layer shown in Part 1. All solution procedures and basic low profiles are the same as in Part 1. The effect of density gradients on the 3-D modes present in the density ratios considered in Part 1 are investigated.

  6. Mass effect of redox reactions: A novel mode for surface plasmon resonance-based bioanalysis.

    PubMed

    Yuan, Pei-Xin; Deng, Sheng-Yuan; Xin, Peng; Ji, Xu-Bo; Shan, Dan; Cosnier, Serge

    2015-12-15

    The pursuit of more specific and sensitive response is a perpetual goal for modern bioassays. This work proposed a novel label-free strategy about redox-related mass effect based on the surface plasmon resonance (SPR) technique for ultrasensitive determination of DNA. The protocol starts with the modification of SPR gilded disk with the capture DNA (cDNA). After the conjugation of immobilized cDNA with the target DNA (tDNA), the hybridization chain reaction was triggered by the introduction of mutual partial complementary primers to elongate the terminal into a nanoscale duplex. As it is reported that porphyrin could intercalate into the grooves of the double-stranded DNA (dsDNA) scaffold, multiple positive-charged Fe(III)meso-tetra(N-methyl-4-pyridyl) porphine (FeTMPyP) with symmetric structure were uptaken for in situ formation of porphyrin-dsDNA complex. Given FeTMPyP a highly efficient catalysis for the peroxide reduction, its presence as a biomimetic cofactor was validated via circular dichroism and UV-vis spectroscopy, demonstrating a tight binding as well as high catalytic activity and stability. Using 4-chloro-1-naphthol as a proton donor, the catalytic reduction of H2O2 would oxidize it into insoluble benzo-4-chloro-hexadienone, which simultaneously deposited on the heterogeneous interface, leading to a significant amplification in both SPR response and topological height profile. The signal increment was proportional to the concentration of tDNA, thus an ultrasensitive SPR-based DNA assay was developed with a linear range over four orders of magnitudes and a sub-femtomolar detection limit of 0.73 fM. The developed methodology exemplifies a different way of thinking about mass-sensing modes, extending conventional SPR-based DNA analysis to relevant biomedical applications. PMID:26141105

  7. Mass effect of redox reactions: A novel mode for surface plasmon resonance-based bioanalysis.

    PubMed

    Yuan, Pei-Xin; Deng, Sheng-Yuan; Xin, Peng; Ji, Xu-Bo; Shan, Dan; Cosnier, Serge

    2015-12-15

    The pursuit of more specific and sensitive response is a perpetual goal for modern bioassays. This work proposed a novel label-free strategy about redox-related mass effect based on the surface plasmon resonance (SPR) technique for ultrasensitive determination of DNA. The protocol starts with the modification of SPR gilded disk with the capture DNA (cDNA). After the conjugation of immobilized cDNA with the target DNA (tDNA), the hybridization chain reaction was triggered by the introduction of mutual partial complementary primers to elongate the terminal into a nanoscale duplex. As it is reported that porphyrin could intercalate into the grooves of the double-stranded DNA (dsDNA) scaffold, multiple positive-charged Fe(III)meso-tetra(N-methyl-4-pyridyl) porphine (FeTMPyP) with symmetric structure were uptaken for in situ formation of porphyrin-dsDNA complex. Given FeTMPyP a highly efficient catalysis for the peroxide reduction, its presence as a biomimetic cofactor was validated via circular dichroism and UV-vis spectroscopy, demonstrating a tight binding as well as high catalytic activity and stability. Using 4-chloro-1-naphthol as a proton donor, the catalytic reduction of H2O2 would oxidize it into insoluble benzo-4-chloro-hexadienone, which simultaneously deposited on the heterogeneous interface, leading to a significant amplification in both SPR response and topological height profile. The signal increment was proportional to the concentration of tDNA, thus an ultrasensitive SPR-based DNA assay was developed with a linear range over four orders of magnitudes and a sub-femtomolar detection limit of 0.73 fM. The developed methodology exemplifies a different way of thinking about mass-sensing modes, extending conventional SPR-based DNA analysis to relevant biomedical applications.

  8. Zero-mode clad waveguides for performing spectroscopy with confined effective observation volumes

    DOEpatents

    Levene, Michael J.; Korlach, Jonas; Turner, Stephen W.; Craighead, Harold G.; Webb, Watt W.

    2005-07-12

    The present invention is directed to a method and an apparatus for analysis of an analyte. The method involves providing a zero-mode waveguide which includes a cladding surrounding a core where the cladding is configured to preclude propagation of electromagnetic energy of a frequency less than a cutoff frequency longitudinally through the core of the zero-mode waveguide. The analyte is positioned in the core of the zero-mode waveguide and is then subjected, in the core of the zero-mode waveguide, to activating electromagnetic radiation of a frequency less than the cut-off frequency under conditions effective to permit analysis of the analyte in an effective observation volume which is more compact than if the analysis were carried out in the absence of the zero-mode waveguide.

  9. Effect of Buckling Modes on the Fatigue Life and Damage Tolerance of Stiffened Structures

    NASA Technical Reports Server (NTRS)

    Davila, Carlos G.; Bisagni, Chiara; Rose, Cheryl A.

    2015-01-01

    The postbuckling response and the collapse of composite specimens with a co-cured hat stringer are investigated experimentally and numerically. These specimens are designed to evaluate the postbuckling response and the effect of an embedded defect on the collapse load and the mode of failure. Tests performed using controlled conditions and detailed instrumentation demonstrate that the damage tolerance, fatigue life, and collapse loads are closely tied with the mode of the postbuckling deformation, which can be different between two nominally identical specimens. Modes that tend to open skin/stringer defects are the most damaging to the structure. However, skin/stringer bond defects can also propagate under shearing modes. In the proposed paper, the effects of initial shape imperfections on the postbuckling modes and the interaction between different postbuckling deformations and the propagation of skin/stringer bond defects under quasi-static or fatigue loads will be examined.

  10. Linear and nonlinear effect of sheared plasma flow on resistive tearing modes

    SciTech Connect

    Hu, Qiming Hu, Xiwei; Yu, Q.

    2014-12-15

    The effect of sheared plasma flow on the m/n = 2/1 tearing mode is studied numerically (m and n are the poloidal and toroidal mode numbers). It is found that in the linear phase the plasma flow with a weak or moderate shear plays a stabilizing effect on tearing mode. However, the mode is driven to be more unstable by sufficiently strong sheared flow when approaching the shear Alfvén resonance (AR). In the nonlinear phase, a moderate (strong) sheared flow leads to a smaller (larger) saturated island width. The stabilization of tearing modes by moderate shear plasma flow is enhanced for a larger plasma viscosity and a lower Alfvén velocity. It is also found that in the nonlinear phase AR accelerates the plasma rotation around the 2/1 rational surface but decelerates it at the AR location, and the radial location satisfying AR spreads inwards towards the magnetic axis.

  11. Failure modes and effects analysis of fusion magnet systems

    SciTech Connect

    Zimmermann, M; Kazimi, M S; Siu, N O; Thome, R J

    1988-12-01

    A failure modes and consequence analysis of fusion magnet system is an important contributor towards enhancing the design by improving the reliability and reducing the risk associated with the operation of magnet systems. In the first part of this study, a failure mode analysis of a superconducting magnet system is performed. Building on the functional breakdown and the fault tree analysis of the Toroidal Field (TF) coils of the Next European Torus (NET), several subsystem levels are added and an overview of potential sources of failures in a magnet system is provided. The failure analysis is extended to the Poloidal Field (PF) magnet system. Furthermore, an extensive analysis of interactions within the fusion device caused by the operation of the PF magnets is presented in the form of an Interaction Matrix. A number of these interactions may have significant consequences for the TF magnet system particularly interactions triggered by electrical failures in the PF magnet system. In the second part of this study, two basic categories of electrical failures in the PF magnet system are examined: short circuits between the terminals of external PF coils, and faults with a constant voltage applied at external PF coil terminals. An electromagnetic model of the Compact Ignition Tokamak (CIT) is used to examine the mechanical load conditions for the PF and the TF coils resulting from these fault scenarios. It is found that shorts do not pose large threats to the PF coils. Also, the type of plasma disruption has little impact on the net forces on the PF and the TF coils. 39 refs., 30 figs., 12 tabs.

  12. Effect of Aspect Ratio on H-mode and ELM Characteristics

    NASA Astrophysics Data System (ADS)

    Thome, K. E.; Bodner, G. M.; Bongard, M. W.; Burke, M. G.; Fonck, R. J.; Kriete, D. M.

    2015-11-01

    The H-mode confinement regime is achieved at near-unity aspect ratio (A < 1 . 2) in the Pegasus Toroidal Experiment via high-field-side fueling and low edge recycling. Ohmic H-mode is attained in both limited and diverted magnetic topologies. This regime is characterized by: reduced Dα emissions; increased core rotation; increased central heating; formation of edge current and pressure pedestals; and measured energy confinement consistent with the ITER98pb(y,2) scaling. The H-mode power threshold, PLH , behaves quite differently at low- A when compared with high- A operations. PLH /PLH_ITPA 08 increases sharply as A is lowered and no difference in PLH for limited and diverted plasmas is observed at A ~ 1 . 2 . No minimum in PLH with density is observed. Some of these results are consistent with the FM3 model for the L-H transition. Two classes of ELMs have been observed. Small, Type III-like ELMs are present at low input power and have n <= 4 . At POH >>PLH , they transition to large, Type-I-like ELMs with intermediate 5 < n < 15 . The Type III ELM magnetic structures behave opposite that of high- A plasmas, with n much higher, presumably due to the naturally higher J / B peeling mode drive at low- A . Long-sought measurements of the Jedge (R , t) pedestal collapse during an ELM event show a complex, multimodal pedestal collapse and the subsequent ejection of a current-carrying filament. Work supported by US DOE grant DE-FG02-96ER54375.

  13. [Effects of Has-Fe(III) complex on the photodegradation of 2, 4-D in aqueous environment].

    PubMed

    Yu, Chun-yan; Zhao, Hui-min; Chen, Shuo; Zhang, Yao-bin; Quan, Xie

    2010-02-01

    To elucidate the roles of humic acids (HAs) and iron on the environmental fate and transport of organic pollutants in natural water, the interactions of HAs with Fe(III) were characterized by Fourier transform infrared spectroscopy (FTIR) spectra, Ultraviolet-visible (UV-vis) spectra and fluorescence spectra, indicating the formation of HAs-Fe(III) complex. Electron paramagnetic resonance (EPR) spectra show *OH radicals are generated and can participate in the photoreaction in solutions containing HAs, Fe(III) and HAs-Fe(III) complex. Under Xe lamp irradiation (lamda >290 nm), the photodegradation of 2,4-dichlorophenoxyacetic acid (2,4-D), as a kind of herbicide, followed the pseudo-first-order reaction kinetics. The pseudo-first-order rate constant of 2,4-D photodegradation with the presence of only 2,4-D (2 mg x L(-1)) was 0.007 h(-1). In the presence of HAs (5 mg x L(-1)), Fe(III) (0.2 mmol x L(-1)) and HAs-Fe(III) complex, the rate constants of 2,4-D degradation were 0.004, 0.034 and 0.046 h(-1), respectively. It was interesting to note that in the existence of HAs, 2,4-D photodegradation was inhibited. While in the presence of Fe(III), 2,4-D photodegradation was enhanced. Furthermore, in the coexistence of HAs and Fe(III), HAs-Fe(III) complex showed better increased effect on the photodegradation of 2,4-D than Fe(III) alone.

  14. Spin effects on the instability and propagation modes of electrostatic plasma waves in quantum plasmas

    SciTech Connect

    Ki, Dae-Han; Jung, Young-Dae

    2011-09-19

    The effects of the electron spin interaction on the pure instability and propagation modes of the quantum electrostatic waves are investigated in cold quantum electron plasmas. It is found that the influence of the electron spin interaction increases the group velocity of the propagation mode of the quantum electrostatic wave. In addition, it is shown that the electron spin interaction enhances the growth rate of the instability mode of the quantum electrostatic wave. It is also found that the effects of the electron spin interaction would be more important in the domain of small Fermi wave numbers.

  15. Dispersion effects of high-order-mode fiber on temperature and axial strain discrimination

    NASA Astrophysics Data System (ADS)

    Xu, Yanping; Lu, Ping; Song, Jia; Lu, Ping; Chen, Liang; Bao, Xiaoyi; Dong, Xiaopeng

    2015-09-01

    A new approach utilizing effects of dispersion in the high-order-mode fibers (HOMFs) to effectively discriminate changes in environmental temperature and axial strain is proposed and experimentally demonstrated. Experimental characterization of a HOMF-based fiber modal interferometer with a sandwich fiber structure exhibits excellent agreements with numerical simulation results. A Fourier transform method of interferometry in the spatial frequency domain is adopted to distinguish mode coupling between different core-guided modes. Distinct phase sensitivities of multiple dispersion peaks are extracted by employing a novel phase demodulation scheme to realize dual-parameter sensing.

  16. Effects of strain on the band structure of group-III nitrides

    NASA Astrophysics Data System (ADS)

    Yan, Qimin; Rinke, Patrick; Janotti, Anderson; Scheffler, Matthias; Van de Walle, Chris G.

    2014-09-01

    We present a systematic study of strain effects on the electronic band structure of the group-III-nitrides (AlN, GaN and InN) in the wurtzite phase. The calculations are based on density functional theory with band-gap-corrected approaches including the Heyd-Scuseria-Ernzerhof hybrid functional (HSE) and quasiparticle G0W0 methods. We study strain effects under realistic strain conditions, hydrostatic pressure, and biaxial stress. The strain-induced modification of the band structures is found to be nonlinear; transition energies and crystal-field splittings show a strong nonlinear behavior under biaxial stress. For the linear regime around the experimental lattice parameters, we present a complete set of deformation potentials (acz, act, D1, D2, D3, D4, D5, D6) that allows us to predict the band positions of group-III nitrides and their alloys (InGaN and AlGaN) under realistic strain conditions. The benchmarking G0W0 results for GaN agree well with the HSE data and indicate that HSE provides an appropriate description for the band structures of nitrides. We present a systematic study of strain effects on the electronic band structure of the group-III nitrides (AlN, GaN, and InN). We quantify the nonlinearity of strain effects by introducing a set of bowing parameters. We apply the calculated deformation potentials to the prediction of strain effects on transition energies and valence-band structures of InGaN alloys and quantum wells (QWs) grown on GaN, in various orientations (including c-plane, m-plane, and semipolar). The calculated band gap bowing parameters, including the strain effect for c-plane InGaN, agree well with the results obtained by hybrid functional alloy calculations. For semipolar InGaN QWs grown in (202¯1), (303¯1), and (303¯1¯) orientations, our calculated deformation potentials have provided results for polarization ratios in good agreement with the experimental observations, providing further confidence in the accuracy of our values.

  17. Inversed Vernier effect based single-mode laser emission in coupled microdisks

    PubMed Central

    Li, Meng; Zhang, Nan; Wang, Kaiyang; Li, Jiankai; Xiao, Shumin; Song, Qinghai

    2015-01-01

    Recently, on-chip single-mode laser emissions in coupled microdisks have attracted considerable research attention due to their wide applications. While most of single-mode lasers in coupled microdisks or microrings have been qualitatively explained by either Vernier effect or inversed Vernier effect, none of them have been experimentally confirmed. Here, we studied the mechanism of single-mode laser operation in coupled microdisks. We found that the mode numbers had been significantly reduced to nearly single-mode within a large pumping power range from threshold to gain saturation. The detail laser spectra showed that the largest gain and the first lasing peak were mainly generated by one disk and the laser intensity was proportional to the wavelength detuning of two set of modes. The corresponding theoretical analysis showed that the experimental observations were dominated by internal coupling within one cavity, which was similar to the recently explored inversed Vernier effect in two coupled microrings. We believe our finding will be important for understanding the previous experimental findings and the development of on-chip single-mode laser. PMID:26330218

  18. Effects of amino acid mutations in the pore-forming domain of the hemolytic lectin CEL-III.

    PubMed

    Nagao, Tomonao; Masaki, Risa; Unno, Hideaki; Goda, Shuichiro; Hatakeyama, Tomomitsu

    2016-10-01

    The hemolytic lectin CEL-III forms transmembrane pores in the membranes of target cells. A study on the effect of site-directed mutation at Lys405 in domain 3 of CEL-III indicated that replacements of this residue by relatively smaller residues lead to a marked increase in hemolytic activity, suggesting that moderately destabilizing domain 3 facilitates formation of transmembrane pores through conformational changes.

  19. Effects of amino acid mutations in the pore-forming domain of the hemolytic lectin CEL-III.

    PubMed

    Nagao, Tomonao; Masaki, Risa; Unno, Hideaki; Goda, Shuichiro; Hatakeyama, Tomomitsu

    2016-10-01

    The hemolytic lectin CEL-III forms transmembrane pores in the membranes of target cells. A study on the effect of site-directed mutation at Lys405 in domain 3 of CEL-III indicated that replacements of this residue by relatively smaller residues lead to a marked increase in hemolytic activity, suggesting that moderately destabilizing domain 3 facilitates formation of transmembrane pores through conformational changes. PMID:27101707

  20. Effect of direct dissipative coupling of two competing modes on intensity fluctuations in a quantum-dot-microcavity laser

    NASA Astrophysics Data System (ADS)

    Fanaei, M.; Foerster, A.; Leymann, H. A. M.; Wiersig, J.

    2016-10-01

    We investigate two-mode photon correlations in a quantum-dot-microcavity laser with special emphasis on the effects induced by a direct coupling of two competing modes due to the dissipative character of the laser resonator. Numerical results based on a microscopic semiconductor theory reveal an enhanced autocorrelation of both modes and an enhanced anticorrelation between the modes. A detailed analysis is given in terms of dark and bright modes. It is shown that above the lasing threshold the original modes build up a bright mode coupled to the quantum dots and a dark mode, which interacts only indirectly with the quantum dots. We demonstrate that a populated dark mode can enable an efficient transfer of photons between the two original cavity modes, mediating an effective coupling between them.

  1. Effects of Presentation Mode and Pace Control on Performance in Image Classification.

    PubMed

    van der Corput, Paul; van Wijk, Jarke J

    2014-12-01

    A common task in visualization is to quickly find interesting items in large sets. When appropriate metadata is missing, automatic queries are impossible and users have to inspect all elements visually. We compared two fundamentally different, but obvious display modes for this task and investigated the difference with respect to effectiveness, efficiency, and satisfaction. The static mode is based on the page metaphor and presents successive pages with a static grid of items. The moving mode is based on the conveyor belt metaphor and lets a grid of items slide though the screen in a continuous flow. In our evaluation, we applied both modes to the common task of browsing images. We performed two experiments where 18 participants had to search for certain target images in a large image collection. The number of shown images per second (pace) was predefined in the first experiment, and under user control in the second one. We conclude that at a fixed pace, the mode has no significant impact on the recall. The perceived pace is generally slower for moving mode, which causes users to systematically choose for a faster real pace than in static mode at the cost of recall, keeping the average number of target images found per second equal for both modes. PMID:26356944

  2. Crystallinity effects on scaling properties of photoinduced modes in silver nanoprisms

    SciTech Connect

    Ng, Ming-Yaw; Ho, I-Lin; Chang, Yia-Chung

    2015-02-21

    The crystallinity effects on scaling properties of photoinduced modes in crystalline silver nanoprisms with C{sub 3v} symmetry are studied using a realistic atomistic model and group theory. Among all vibrational modes, photoinduced modes can be identified as those vibrational modes which possess larger in-phase radial atomic displacement and can be projected out by the projected density of states method. We found that the properties of vibrations in silver nanoprisms strongly depend on the particle’s aspect ratio (bisector length over thickness). By considering crystallinity of silver nanoprisms, the dominant modes with the in-plane oscillation become several closely spaced modes, and become obvious for nanoprisms with a smaller aspect ratio. The oscillation spectra show that the dominant planar modes are insensitive to thickness change. On the contrary, the atomic displacements show significantly different patterns for nanoprisms of different thicknesses. We also found that, for nanoprisms with same aspect ratio that is larger than 4, the vibrational properties of dominant modes exhibit scaling similarity. By using a simple linear transformation, the vibration frequencies for large-sized nanoprisms of aspect ratio 6 can be obtained by a corresponding scaling factor. The calculated results are in good agreement with experimental data.

  3. Rotational shear effects on edge harmonic oscillations in DIII-D quiescent H-mode discharges

    NASA Astrophysics Data System (ADS)

    Chen, Xi; Burrell, K. H.; Ferraro, N. M.; Osborne, T. H.; Austin, M. E.; Garofalo, A. M.; Groebner, R. J.; Kramer, G. J.; Luhmann, N. C., Jr.; McKee, G. R.; Muscatello, C. M.; Nazikian, R.; Ren, X.; Snyder, P. B.; Solomon, W. M.; Tobias, B. J.; Yan, Z.

    2016-07-01

    In the quiescent H-mode (QH-mode) regime, edge harmonic oscillations (EHOs) play an important role in avoiding transient edge localized mode (ELM) power fluxes by providing benign and continuous edge particle transport. A detailed theoretical, experimental and modeling comparison has been made of low-n (n  ⩽  5) EHO in DIII-D QH-mode plasmas. The calculated linear eigenmode structure from the extended magentoohydrodynamics (MHD) code M3D-C1 matches closely the coherent EHO properties from external magnetics data and internal measurements using the ECE, BES, ECE-Imaging and microwave imaging reflectometer (MIR) diagnostics, as well as the kink/peeling mode properties found by the ideal MHD code ELITE. Numerical investigations indicate that the low-n EHO-like solutions from M3D-C1 are destabilized by rotation and/or rotational shear while high-n modes are stabilized. This effect is independent of the rotation direction, suggesting that EHOs can be destabilized in principle with rotation in either direction. The modeling results are consistent with observations of EHO, support the proposed theory of the EHO as a low-n kink/peeling mode destabilized by edge E  ×  B rotational shear, and improve our understanding and confidence in creating and sustaining QH-mode in present and future devices.

  4. Effect of Annealing and Cold Work on Mechanical Properties of Beta III Titanium

    NASA Astrophysics Data System (ADS)

    Cai, S.; Bailey, D. M.; Kay, L. E.

    2012-12-01

    Experiments have been carried out to study the effect of annealing and cold work (CW) on the mechanical properties of beta III Ti alloy. Material was annealed at different temperatures above the beta transformation temperature, and then cold drawn to about 53% area reduction. Cyclic tensile test was performed to study the evolution of mechanical properties and the recoverable strain during process. Results show that the effect of annealing and CW is closely related to the stress-induced martensite (SIM) phase transformation. Lower annealing temperature results in higher strength and recoverable strain, which is further increased by CW. A total recoverable strain of ~3.2% was obtained from the annealed and CW sample.

  5. Media Presentation Mode, English Listening Comprehension and Cognitive Load in Ubiquitous Learning Environments: Modality Effect or Redundancy Effect?

    ERIC Educational Resources Information Center

    Chang, Chi-Cheng; Lei, Hao; Tseng, Ju-Shih

    2011-01-01

    Although ubiquitous learning enhances students' access to learning materials, it is crucial to find out which media presentation modes produce the best results for English listening comprehension. The present study examined the effect of media presentation mode (sound and text versus sound) on English listening comprehension and cognitive load.…

  6. Fast and slow transient charging in various III-V field-effect transistors with atomic-layer-deposited-Al2O3 gate dielectric

    NASA Astrophysics Data System (ADS)

    Ramón, Michael E.; Akyol, Tarik; Shahrjerdi, Davood; Young, Chadwin D.; Cheng, Julian; Register, Leonard F.; Banerjee, Sanjay K.

    2013-01-01

    We report measurement of fast transient charging effects (FTCE) in enhancement-mode n-channel GaAs, InP, and In0.53Ga0.47As field-effect transistors (FETs) using Al2O3 as the gate dielectric. The FTCE data reveal superior drive current and enhanced threshold voltage stability for In0.53Ga0.47As FETs. We further report charge pumping measurements for In0.53Ga0.47As transistors, revealing that the majority of interface traps are donor traps, as well as an increased trap density within the Al2O3 bulk. Such data, together with FTCE data, reveal that drain current degradation observed during pulsed I-V measurements is predominantly due to slow oxide traps, underscoring their significance within III-V/high-κ metal-oxide-semiconductor FETs.

  7. Health-beneficial effects of probiotics: Its mode of action.

    PubMed

    Ohashi, Yuji; Ushida, Kazunari

    2009-08-01

    It is now widely recognized that probiotics have health-beneficial effects on humans and animals. Probiotics should survive in the intestinal tract to exert beneficial effects on the host's health. To keep a sufficient level of probiotic bacteria in the gastrointestinal tract, a shorter interval between doses may be required. Although adherence to the intestinal epithelial cell and mucus is not a universal property of probiotics, high ability to adhere to the intestinal surface might strongly interfere with infection of pathogenic bacteria and regulate the immune system. The administration of probiotic Lactobacillus stimulated indigenous Lactobacilli and the production of short-chain fatty acids. This alteration of the intestinal environment should contribute to maintain the host's health. The immunomodulatory effects of probiotics are related to important parts of their beneficial effects. Probiotics may modulate the intestinal immune response through the stimulation of certain cytokine and IgA secretion in intestinal mucosa. The health-beneficial effects, in particular the immunomodulation effect, of probiotics depend on the strain used. Differences in indigenous intestinal microflora significantly alter the magnitude of the effects of a probiotic. Specific probiotic strains suitable for each animal species and their life stage as well as each individual should be found.

  8. Assessment of the effects of As(III) treatment on cyanobacteria lipidomic profiles by LC-MS and MCR-ALS.

    PubMed

    Marques, Aline S; Bedia, Carmen; Lima, Kássio M G; Tauler, Romà

    2016-08-01

    Cyanobacteria are a group of photosynthetic, nitrogen-fixing bacteria present in a wide variety of habitats such as freshwater, marine, and terrestrial ecosystems. In this work, the effects of As(III), a major toxic environmental pollutant, on the lipidomic profiles of two cyanobacteria species (Anabaena and Planktothrix agardhii) were assessed by means of a recently proposed method based on the concept of regions of interest (ROI) in liquid chromatography mass spectroscopy (LC-MS) together with multivariate curve resolution alternating least squares (MCR-ALS). Cyanobacteria were exposed to two concentrations of As(III) for a week, and lipid extracts were analyzed by ultrahigh-performance liquid chromatography/time-of-flight mass spectrometry in full scan mode. The data obtained were compressed by means of the ROI strategy, and the resulting LC-MS data sets were analyzed by the MCR-ALS method. Comparison of profile peak areas resolved by MCR-ALS in control and exposed samples allowed the discrimination of lipids whose concentrations were changed due to As(III) treatment. The tentative identification of these lipids revealed an important reduction of the levels of some galactolipids such as monogalactosyldiacylglycerol, the pigment chlorophyll a and its degradation product, pheophytin a, as well as carotene compounds such as 3-hydroxycarotene and carotene-3,3'-dione, all of these compounds being essential in the photosynthetic process. These results suggested that As(III) induced important changes in the composition of lipids of cyanobacteria, which were able to compromise their energy production processes. Graphical abstract Steps of the proposed LC-MS + MCR-ALS procedure. PMID:27311955

  9. Mode Summation Approach to Casimir Effect Between Two Objects

    NASA Astrophysics Data System (ADS)

    Teo, L. P.

    2012-10-01

    In the last few years, several approaches have been developed to compute the exact Casimir interaction energy between two nonplanar objects, all lead to the same functional form, which is called the TGTG formula. In this paper, we explore the TGTG formula from the perspective of mode summation approach. Both scalar fields and electromagnetic fields are considered. In this approach, one has to first solve the equation of motion to find a wave basis for each object. The two T's in the TGTG formula are T-matrices representing the Lippmann-Schwinger T-operators, one for each of the objects. Each T-matrix can be found by matching the boundary conditions imposed on the object, and it is independent of the other object. However, it depends on whether the object is interacting with an object outside it, or an object inside it. The two G's in the TGTG formula are the translation matrices, relating the wave basis of an object to the wave basis of the other object. These translation matrices only depend on the wave basis chosen for each object, and they are independent of the boundary conditions on the objects. After discussing the general theory, we apply the prescription to derive the explicit formulas for the Casimir energies for the sphere-sphere, sphere-plane, cylinder-cylinder and cylinder-plane interactions. First the T-matrices for a plane, a sphere and a cylinder are derived for the following cases: the object is imposed with Dirichlet, Neumann or general Robin boundary conditions; the object is semitransparent; and the object is a magnetodielectric object immersed in a magnetodielectric media. Then the operator approach developed by R. C. Wittman [IEEE Trans. Antennas Propag.36, 1078 (1988)] is used to derive the translation matrices. From these, the explicit TGTG formula for each of the scenarios can be written down. On the one hand, we have summarized all the TGTG formulas that have been derived so far for the sphere-sphere, cylinder-cylinder, sphere-plane and

  10. Communication: Effects of thermionic-gun parameters on operating modes in ultrafast electron microscopy.

    PubMed

    Kieft, Erik; Schliep, Karl B; Suri, Pranav K; Flannigan, David J

    2015-09-01

    Ultrafast electron microscopes with thermionic guns and LaB6 sources can be operated in both the nanosecond, single-shot and femtosecond, single-electron modes. This has been demonstrated with conventional Wehnelt electrodes and absent any applied bias. Here, by conducting simulations using the General Particle Tracer code, we define the electron-gun parameter space within which various modes may be optimized. The properties of interest include electron collection efficiency, temporal and energy spreads, and effects of laser-pulse duration incident on the LaB6 source. We find that collection efficiencies can reach 100% for all modes, despite there being no bias applied to the electrode.

  11. Theory of energetic/alpha particle effects on magnetohydrodynamic modes in tokamaks

    SciTech Connect

    Chen, L.; White, R.B.; Rewoldt, G.; Colestock, P.; Rutherford, P.H.; Chen, Y.P.; Ke, F.J.; Tsai, S.T.; Bussac, M.N.

    1989-01-01

    The presence of energetic particles is shown to qualitatively modify the stability properties of ideal as well as resistive magnetohydrodynamic (MHD) modes in tokamaks. Specifically, we demonstrate that, consistent with highpower ICRF heating experiments in JET, high energy trapped particles can effectively stabilize the sawtooth mode, providing a possible route to stable high current tokamak operation. An alternative stabilization scheme employing barely circulating energetic particles is also proposed. Finally, we present analytical and numerical studies on the excitations of high-n MHD modes via transit resonances with circulating alpha particles. 14 refs., 3 figs.

  12. Effect of Oxidation Rate and Fe(II) State on Microbial Nitrate-Dependent Fe(III) Mineral Formation

    PubMed Central

    Senko, John M.; Dewers, Thomas A.; Krumholz, Lee R.

    2005-01-01

    A nitrate-dependent Fe(II)-oxidizing bacterium was isolated and used to evaluate whether Fe(II) chemical form or oxidation rate had an effect on the mineralogy of biogenic Fe(III) (hydr)oxides resulting from nitrate-dependent Fe(II) oxidation. The isolate (designated FW33AN) had 99% 16S rRNA sequence similarity to Klebsiella oxytoca. FW33AN produced Fe(III) (hydr)oxides by oxidation of soluble Fe(II) [Fe(II)sol] or FeS under nitrate-reducing conditions. Based on X-ray diffraction (XRD) analysis, Fe(III) (hydr)oxide produced by oxidation of FeS was shown to be amorphous, while oxidation of Fe(II)sol yielded goethite. The rate of Fe(II) oxidation was then manipulated by incubating various cell concentrations of FW33AN with Fe(II)sol and nitrate. Characterization of products revealed that as Fe(II) oxidation rates slowed, a stronger goethite signal was observed by XRD and a larger proportion of Fe(III) was in the crystalline fraction. Since the mineralogy of Fe(III) (hydr)oxides may control the extent of subsequent Fe(III) reduction, the variables we identify here may have an effect on the biogeochemical cycling of Fe in anoxic ecosystems. PMID:16269756

  13. Bi-fluid and neoclassical effect on a Double-Tearing mode in Tore Supra

    SciTech Connect

    Maget, Patrick Garbet, Xavier; Février, Olivier; Ségui, Jean-Luc; Lütjens, Hinrich; Luciani, Jean-François

    2014-06-15

    Tearing modes associated to hollow current profiles are prone to grow in moderate performance plasmas and often constrain the realization of non-inductive discharges in the Tore Supra tokamak, where long pulse duration is performed using Lower Hybrid waves for providing most of the plasma current. The prediction of MHD boundaries in such scenarios is complicated by the importance of diamagnetic effects, combined with curvature stabilization, which determine the stability of these modes. We show that diamagnetic effects, as well as neoclassical forces, are playing a key role in the linear and nonlinear regimes of Double-Tearing Modes on q = 5/3 and q = 2 in these experimental conditions. Detailed comparison with experimental measurements, combined with a scaling in plasma resistivity, give constraints about the experimental equilibrium. Resistive-Interchange Modes destabilized by diamagnetic rotation could also play a role in degrading the energy confinement in the negative magnetic shear region.

  14. The detection rate of inspiral and quasi-normal modes of Population III binary black holes which can confirm or refute the general relativity in the strong gravity region

    NASA Astrophysics Data System (ADS)

    Kinugawa, Tomoya; Miyamoto, Akinobu; Kanda, Nobuyuki; Nakamura, Takashi

    2016-02-01

    Using our population synthesis code, we found that the typical chirp mass defined by (m1m2)3/5/(m1 + m2)1/5 of Population III (Pop III) binary black holes (BH-BHs) is ˜30 M⊙ with the total mass of ˜60 M⊙ so that the inspiral chirp signal as well as quasi-normal mode (QNM) of the merging black hole (BH) are interesting targets of KAGRA. The detection rate of the coalescing Pop III BH-BHs is ˜180 events yr- 1 (SFRp/(10-2.5 M⊙ yr-1 Mpc-3))([fb/(1 + fb)]/0.33)Errsys in our standard model, where SFRp, fb and Errsys are the peak value of the Pop III star formation rate, the binary fraction and the systematic error with Errsys = 1 for our standard model, respectively. To evaluate the robustness of chirp mass distribution and the range of Errsys, we examine the dependence of the results on the unknown parameters and the distribution functions in the population synthesis code. We found that the chirp mass has a peak at ˜30 M⊙ in most of parameters and distribution functions as well as Errsys ranges from 0.046 to 4. Therefore, the detection rate of the coalescing Pop III BH-BHs ranges about 8.3-720 events yr- 1(SFRp/(10- 2.5 M⊙ yr- 1 Mpc- 3))([fb/(1 + fb)]/0.33). The minimum rate corresponds to the worst model which we think unlikely so that unless (SFRp/(10- 2.5 M⊙ yr- 1 Mpc- 3))([fb/(1 + fb)]/0.33) ≪ 0.1, we expect the Pop III BH-BHs merger rate of at least one event per year by KAGRA. Nakano, Tanaka & Nakamura show that if signal-to-noise ratio (S/N) of QNM is larger than 35, we can confirm or refute the general relativity (GR) more than 5σ level. In our standard model, the detection rate of Pop III BH-BHs whose S/N is larger than 35 is 3.2 events yr- 1 (SFRp/(10- 2.5 M⊙ yr- 1 Mpc- 3))([fb/(1 + fb)]/0.33)Errsys. Thus, there is a good chance to check whether GR is correct or not in the strong gravity region.

  15. Silver nanoparticles-enhanced rare earth co-luminescence effect of Tb(III)-Y(III)-dopamine system.

    PubMed

    Li, Huihui; Wu, Xia

    2015-06-01

    It was found that silver nanoparticles (AgNPs) could enhance co-luminescence effect of rare earths ions Tb(3+) and Y(3+). Based on this, a sensitive fluorescence detection method for the determination of dopamine (DA) was proposed. Moreover, the detection limit for DA was very low (down to nM). This is because DA can remarkably enhance the luminescence intensity of the Tb(3+) ion by Y(3+) in the colloidal solution of AgNPs, forming a new co-luminescence system. Furthermore, based on the metal enhanced fluorescence (MEF), AgNPs can sensitize the co-luminescence effect of the complex of Tb(3+)-Y(3+)-DA. In a neutral buffer solution (pH 7.50), the luminescence intensity of the system was linearly related to the concentration of DA in the range of 2.0-100 nM, with a limit of detection as low as 0.57 nM. The proposed method was applied for the determination of DA in dopamine hydrochloride injections and human serum samples with good accuracy and satisfactory recovery.

  16. Effect of III-V on insulator structure on quantum well intermixing

    NASA Astrophysics Data System (ADS)

    Takashima, Seiya; Ikku, Yuki; Takenaka, Mitsuru; Takagi, Shinichi

    2016-04-01

    To achieve the monolithic active/passive integration on the III-V CMOS photonics platform, quantum well intermixing (QWI) on III-V on insulator (III-V-OI) is studied for fabricating multi-bandgap III-V-OI wafers. By optimizing the QWI condition for a 250-nm-thick III-V layer, which contains a five-layer InGaAsP-based multi-quantum well (MQW) with 80-nm-thick indium phosphide (InP) cladding layers, we have successfully achieved a photoluminescence (PL) peak shift of over 100 nm on the III-V-OI wafer. We have also found that the progress of QWI on the III-V-OI wafer is slower than that on the InP bulk wafer regardless of the buried oxide (BOX) thickness, bonding interface materials, and handle wafers. We have also found that the progress of QWI on the III-V-OI wafer is slower than that on the InP bulk wafer regardless of the buried oxide (BOX) thickness, bonding interface materials, and bulk support wafers on which the III-V-OI structure is formed (handle wafers). By comparing between the measured PL shift and simulated diffusions of phosphorus vacancies and interstitials during QWI, we have found that the slow QWI progress in the III-V-OI wafer is probably attributed to the enhanced recombination of vacancies and interstitials by the diffusion blocking of vacancies and interstitials at the BOX interface.

  17. Effect of desferrioxamine B and Suwannee River fulvic acid on Fe(III) release and Cr(III) desorption from goethite

    NASA Astrophysics Data System (ADS)

    Stewart, Angela G.; Hudson-Edwards, Karen A.; Dubbin, William E.

    2016-04-01

    Siderophores are biogenic chelating ligands that facilitate the solubilisation of Fe(III) and form stable complexes with a range of contaminant metals and therefore may significantly affect their biogeochemical cycling. Desferrioxamine B (DFOB) is a trihydroxamate siderophore that acts synergistically with fulvic acid and low molecular weight organic ligands to release Fe from Fe(III) oxides. We report the results of batch dissolution experiments in which we determine the rates of Cr(III) desorption and Fe(III) release from Cr(III)-treated synthetic goethite as influenced by DFOB, by fulvic acid, and by the two compounds in combination. We observed that adsorbed Cr(III) at 3% surface coverage significantly reduced Fe(III) release from goethite for all combinations of DFOB and fulvic acid. When DFOB (270 μM) was the only ligand present, dissolved Fe(III) and Cr(III) increased approximately 1000-fold and 16-fold, respectively, as compared to the ligand-free system, a difference we attribute to the slow rate of water exchange of Cr(III). Suwannee River fulvic acid (SRFA) acts synergistically with DFOB by (i) reducing the goethite surface charge leading to increased HDFOB+ surface excess and by (ii) forming aqueous Fe(III)-SRFA species whose Fe(III) is subsequently removed by DFOB to yield aqueous Fe(III)-DFOB complexes. These observations shed new light on the synergistic relationship between DFOB and fulvic acid and reveal the mechanisms of Fe(III) acquisition available to plants and micro-organisms in Cr(III) contaminated environments.

  18. Effects of heavy modes on vacuum stability in supersymmetric theories

    NASA Astrophysics Data System (ADS)

    Brizi, Leonardo; Scrucca, Claudio A.

    2010-11-01

    We study the effects induced by heavy fields on the masses of light fields in supersymmetric theories, under the assumption that the heavy mass scale is much higher than the supersymmetry breaking scale. We show that the square-masses of light scalar fields can get two different types of significant corrections when a heavy multiplet is integrated out. The first is an indirect level-repulsion effect, which may arise from heavy chiral multiplets and is always negative. The second is a direct coupling contribution, which may arise from heavy vector multiplets and can have any sign. We then apply these results to the sGoldstino mass and study the implications for the vacuum metastability condition. We find that the correction from heavy chiral multiplets is always negative and tends to compromise vacuum metastability, whereas the contribution from heavy vector multiplets is always positive and tends on the contrary to reinforce it. These two effects are controlled respectively by Yukawa couplings and gauge charges, which mix one heavy and two light fields respectively in the superpotential and the Kähler potential. Finally we also comment on similar effects induced in soft scalar masses when the heavy multiplets couple both to the visible and the hidden sector.

  19. The Effect of Mode of Feedback in Microteaching.

    ERIC Educational Resources Information Center

    Shively, Joe E.; And Others

    A study examined the effects on teacher performance and attitudes of several manipulations of the conditions under which the microteaching supervisor provides feedback: he bases his critique on (1) a videotape of the microteaching lesson which he views with the microteaching teacher (VT group); (2) an audiotape instead (AT group); (3) his…

  20. ANAEROBIC DIGESTION OF ANIMAL WASTE: EFFECT OF MODE OF MIXING

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Laboratory-scale digesters were operated to study the effect of mixing (via biogas recirculation, impeller mixing, and slurry recirculation) on biogas production. Three sets of experiments were performed using cow manure slurry feed with either 50, 100, or 150 g/L total solids (TS) concentrations (r...

  1. The formation of Population III stars and their effect on cosmological structure in the early universe

    NASA Astrophysics Data System (ADS)

    O'Shea, Brian William

    2005-11-01

    The first generation of stars to form in the universe have a profound impact on their environment. These stars are responsible for beginning the universe's transition from a "cosmic dark age" where no sources of visible light existed; to the bright universe seen today. Additionally, these stars were believed to be the first sources of all elements heavier than lithium, which strongly affected the ability of gas to cool and permanently changed how star formation occurred. In this dissertation I present results from numerical simulations of the formation of the first generation of stars to form in the universe ("Population III" stars) and their effects on later structure formation. I compare Enzo, the adaptive mesh refinement cosmology code used to perform all of the simulations in this work, to GADGET, a smoothed particle hydrodynamics cosmology code. Nearly identical results can be obtained when using two extremely different numerical methods, which helps to verify the correctness of both codes and strengthen the confidence of predictions made with these tools. I perform high dynamical range calculations of the formation of an ensemble of Population III stars, varying multiple simulation parameters, in a standard cold dark matter cosmology as well as with a soft ultraviolet background and in a generic warm dark matter cosmology. I find that the accretion rates of primordial protostars have been systematically overestimated by previously published work, which has profound implications for later structure formation and the reionization of the universe. Additionally, the presence of a soft ultraviolet background and warm dark matter serves to delay the onset of star formation. I propose limits on the possible mass of a warm dark matter particle. I also present results of simulations which demonstrate the effects of the HII regions and metal enrichment from Population III stars. It appears that HII regions from these stars may hasten the formation of later generations

  2. Effect of phosphate and sulfate on Ni repartitioning during Fe(II)-catalyzed Fe(III) oxide mineral recrystallization

    NASA Astrophysics Data System (ADS)

    Hinkle, Margaret A. G.; Catalano, Jeffrey G.

    2015-09-01

    Dissolved Fe(II) activates coupled oxidative growth and reductive dissolution of Fe(III) oxide minerals, causing recrystallization and the repartitioning of structurally-compatible trace metals. Phosphate and sulfate, two ligands common to natural aquatic systems, alter Fe(II) adsorption onto Fe(III) oxides and affect Fe(III) oxide dissolution and precipitation. However, the effect of these oxoanions on trace metal repartitioning during Fe(II)-catalyzed Fe(III) oxide recrystallization is unclear. The effects of phosphate and sulfate on Ni adsorption and Ni repartitioning during Fe(II)-catalyzed Fe(III) oxide recrystallization were investigated as such repartitioning may be affected by both Fe(II)-oxoanion and metal-oxoanion interactions. In most systems examined, phosphate alters Ni repartitioning during Fe(II)-catalyzed recrystallization to a larger extent than sulfate. Phosphate substantially enhances Ni adsorption onto hematite but decreases (nearly inhibiting) Fe(II)-catalyzed Ni incorporation into and release from this mineral. In the goethite system, however, phosphate suppresses Ni release but enhances Ni incorporation in the presence of aqueous Fe(II). In contrast, sulfate has little effect on macroscopic Ni adsorption and release of Ni from Fe(III) oxides, but substantially enhances Ni incorporation into goethite. This demonstrates that phosphate and sulfate have unique, mineral-specific interactions with Ni during Fe(II)-catalyzed Fe(III) oxide recrystallization. This research suggests that micronutrient bioavailability at redox interfaces in hematite-dominated systems may be especially suppressed by phosphate, while both oxoanions likely have limited effects in goethite-rich soils or sediments. Phosphate may also exert a large control on contaminant fate at redox interfaces, increasing Ni retention on iron oxide surfaces. These results further indicate that trace metal retention by iron oxides during lithification and later repartitioning during

  3. Hexacyanoferrate(III) transport in coated montmorillonite clay films. Effects of water-soluble polymers

    SciTech Connect

    Sequaris, J.M.

    2000-02-08

    Hexacyanoferrate(III) Fe(CN){sub 6}{sup 3{minus}}, transport through coated montmorillonite clay films at a platinum electrode is studied with the cyclic voltammetric method. Experimental conditions are first established guaranteeing voltammetric detection based on a linear diffusion in the clay film. The square of the ratio (R{sup 2}) of current intensities obtained at the clay modified electrode (CME) and the bare Pt electrode measures the relative variation of the Fe(CN){sub 6}{sup 3{minus}}, diffusion coefficient in the clay film. Thus, the effects of bathing electrolyte concentrations on R{sup 2} are investigated and related to the swelling properties of the montmorillonite clay characterized by X-ray diffraction and sedimentation volume results.

  4. Hydrogen effects in dilute III-N-V alloys: From defect engineering to nanostructuring

    SciTech Connect

    Pettinari, G.; Felici, M.; Capizzi, M.; Polimeni, A.; Trotta, R.

    2014-01-07

    The variation of the band gap energy of III-N-V semiconductors induced by hydrogen incorporation is the most striking effect that H produces in these materials. A special emphasis is given here to the combination of N-activity passivation by hydrogen with H diffusion kinetics in dilute nitrides. Secondary ion mass spectrometry shows an extremely steep (smaller than 5 nm/decade) forefront of the H diffusion profile in Ga(AsN) under appropriate hydrogenation conditions. This discovery prompts the opportunity for an in-plane nanostructuring of hydrogen incorporation and, hence, for a modulation of the material band gap energy at the nanoscale. The properties of quantum dots fabricated by a lithographically defined hydrogenation are presented, showing the zero-dimensional character of these novel nanostructures. Applicative prospects of this nanofabrication method are finally outlined.

  5. Comments on the somatic effects section of the BEIR III report

    SciTech Connect

    Rossi, H.H.

    1980-12-01

    The recent report of the BEIR Committee of the National Academy of Sciences presents a wide range of risk estimates for radiogenic cancer. The values that can be considered to be most plausible on the basis of radiobiological and epidemiological evidence are given little emphasis and they are presented as lower bounds of the probable risk. The upper bound is said to be provided by estimates based on the so-called linear hypothesis. The preferred analysis in BEIR III requires an arbitrary choice of a critical parameter. This results in estimates that differ little from those given in BEIR I and that may be too high by an order of magnitude. It also refuses to speculate on any health effects of background radiation. It thus does not support the validity of those concepts of radiation protection that are based on linearity.

  6. Effect of dark matter halo on global spiral modes in galaxies

    NASA Astrophysics Data System (ADS)

    Ghosh, Soumavo; Saini, Tarun Deep; Jog, Chanda J.

    2016-02-01

    Low surface brightness (LSB) galaxies form a major class of galaxies, and are characterized by low disc surface density and low star formation rate. These are known to be dominated by dark matter halo from the innermost regions. Here, we study the role of the dark matter halo on the grand-design, m = 2, spiral modes in a galactic disc by carrying out a global mode analysis in the WKB approximation. The Bohr-Sommerfeld quantization rule is used to determine how many discrete global spiral modes are permitted. First, a typical superthin, LSB galaxy UGC 7321 is studied by taking only the galactic disc, modelled as a fluid; and then the disc embedded in a dark matter halo. We find that both cases permit the existence of global spiral modes. This is in contrast to earlier results where the inclusion of dark matter halo was shown to nearly fully suppress local, swing-amplified spiral features. Although technically global modes are permitted in the fluid model as shown here, we argue that due to lack of tidal interactions, these are not triggered in LSB galaxies. For comparison, we carried out a similar analysis for the Galaxy, for which the dark matter halo does not dominate in the inner regions. We show that here too the dark matter halo has little effect, hence the disc embedded in a halo is also able to support global modes. The derived pattern speed of the global mode agrees fairly well with the observed value for the Galaxy.

  7. The growth of the tearing mode - Boundary and scaling effects

    NASA Technical Reports Server (NTRS)

    Steinolfson, R. S.; Van Hoven, G.

    1983-01-01

    A numerical model of resistive magnetic tearing is developed in order to verify and relate the results of the principal approximations used in analytic analyses and to investigate the solutions and their growth-rate scalings over a large range of primary parameters which include parametric values applicable to the solar atmosphere. The computations cover the linear behavior for a variety of boundary conditions, emphasizing effects which differentiate magnetic tearing in astrophysical situations from that in laboratory devices. Eigenfunction profiles for long and short wavelengths are computed and the applicability of the 'constant psi' approximation is investigated. The growth rate is computed for values of the magnetic Reynolds number up to a trillion and of the dimensionless wavelength parameter down to 0.001. The analysis predicts significant effects due to differing values of the magnetic Reynolds number.

  8. Effect Of Clock Mode On Radiation Hardness Of An ADC

    NASA Technical Reports Server (NTRS)

    Lee, Choon I.; Rax, Bernie G.; Johnston, Allan H.

    1995-01-01

    Report discusses techniques for testing and evaluating effects of total dosages of ionizing radiation on performances of high-resolution successive-approximation analog-to-digital converters (ADCs), without having to test each individual bit or transition. Reduces cost of testing by reducing tests to few critical parametric measurements, from which one determines approximate radiation failure levels providing good approximations of responses of converters for purpose of total-dose-radiation evaluations.

  9. Effect of dynamical friction on nonlinear energetic particle modes

    SciTech Connect

    Lilley, M. K.; Breizman, B. N.; Sharapov, S. E.

    2010-09-15

    A fully nonlinear model is developed for the bump-on-tail instability including the effects of dynamical friction (drag) and velocity space diffusion on the energetic particles driving the wave. The results show that drag provides a destabilizing effect on the nonlinear evolution of waves. Specifically, in the early nonlinear phase of the instability, the drag facilitates the explosive scenario of the wave evolution, leading to the creation of phase space holes and clumps that move away from the original eigenfrequency. Later in time, the electric field associated with a hole is found to be enhanced by the drag, whereas for a clump it is reduced. This leads to an asymmetry of the frequency evolution between holes and clumps. The combined effect of drag and diffusion produces a diverse range of nonlinear behaviors including hooked frequency chirping, undulating, and steady state regimes. An analytical model is presented, which explains the aforementioned diversity. A continuous production of hole-clump pairs in the absence of collisions is also observed.

  10. Subchronic administration of riparin III induces antidepressive-like effects and increases BDNF levels in the mouse hippocampus.

    PubMed

    Vasconcelos, Auriana S; Oliveira, Iris C M; Vidal, Laura T M; Rodrigues, Gabriel C; Gutierrez, Stanley J C; Barbosa-Filho, José M; Vasconcelos, Silvânia M M; de França Fonteles, Marta M; Gaspar, Danielle M; de Sousa, Francisca C F

    2015-08-01

    Riparin III (Rip III) is an alcamide isolated from Aniba riparia that has presented effects of antidepressant and anxiolytic activities in acute stress behavioral models. The trial's goal was to investigate the activity of Rip III in mice exposed to corticosterone-induced chronic depression model. Swiss female mice, 22-25 g, were distributed in following experimental groups: control group (vehicle1: saline containing 0.1% dimethyl sulfoxide and 0.1% Tween-80, SC+ vehicle 2: distilled water emulsified with 2% Tween-80, PO); stressed group (corticosterone, 20 mg/kg, SC, + vehicle 2, orally); Rip III group (50 mg/kg, orally); and fluvoxamine (Flu) group (50 mg/kg, orally). The mice were exposed to the behavioral tests, and posteriorly, Brain-derived neurotrophic factor protein levels were assessed in hippocampal samples. Statistical analysis of the data was performed by one-way anova, followed by Newman-Keuls test. Both administrations of Rip III and Flu significantly reduced the immobility time in tail suspension and forced swimming tests after 21 days without affecting locomotor function. There was also an increase in BDNF protein levels in the mice hippocampus. These findings further support the hypothesis that Rip III could be a new pharmacological target for the treatment of mood disorders.

  11. Cr(III) exerts stronger structural effects than Cr(VI) on the human erythrocyte membrane and molecular models.

    PubMed

    Suwalsky, M; Castro, R; Villena, F; Sotomayor, C P

    2008-04-01

    Chromium exists in many oxidation states, of which only the hexavalent Cr(VI) and the trivalent Cr(III) ions are stable under environmental conditions. It is generally reported that Cr(VI) is highly toxic while Cr(III) is relatively innocuous, although others have reported just the opposite. On the other hand, despite the many studies on chromium toxicity, and particularly after the knowledge that Cr(VI) anions readily enter the erythrocytes where they are reduced to Cr(III), there are practically no reports on the structural effects induced by chromium compounds on the erythrocyte membrane. With the aim to better understand the molecular mechanisms of the interaction of Cr(III) and Cr(VI) with cell membranes, CrCl(3), and K(2)CrO(4) were incubated with intact erythrocytes, isolated unsealed human erythrocyte membranes (IUM), and molecular models of the erythrocyte membrane. These consisted in bilayers built-up of dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylcholine (DMPE), phospholipid classes present in the outer and inner monolayers of the erythrocyte membrane, respectively. The capacity of Cr(III) and Cr(VI) to perturb the bilayer structures of DMPC and DMPE was evaluated by X-ray diffraction, DMPC large unilamellar vesicles (LUV) and IUM were studied by fluorescence spectroscopy, and intact human erythrocytes were observed with scanning electron microscopy (SEM). In all these systems, it was found that Cr(III) induced considerably higher structural perturbations than Cr(VI). PMID:18234343

  12. O-Mode and X-Mode Coupling Effects in Toroidal Plasmas at Fundamental and Second EC Harmonics and Implication for Iter

    NASA Astrophysics Data System (ADS)

    Vdovin, V. L.

    2011-02-01

    We present recent numerically well resolved ECRF 3D STELEC toroidal full wave code [1] modelling results for fundamental and second harmonics scenarios in several tokamaks and ITER. Improved numerical resolution for middle size tokamaks further solidly confirms previously discovered O- and X- modes strong coupling at fundamental harmonic leading to broadened power deposition profiles, in compare with ray tracing predictions, due to influence of Upper Hybrid Resonance (UHR). For the T-10/DIII-D tokamaks we consider O-mode outside launch cases with EC resonance in plasma with UHR usual "moon serp" surface and out off plasma EC resonance at High Field Side when UHR surface is in-plasma internally closed one with Electron Bernstein Waves (EBW) being excited inside of it due to mode conversion process. Combined self consistent dynamic O-mode, X-mode and EB waves structure is intriguing one and is shown. This out off plasma EC fundamental resonance scenario was discovered in WEGA stellarator [2]. In second harmonic scenarios we are concentrating on X-mode outside launch at sufficiently large plasma densities for JET, some times close (but lower) to this mode density cut off. Exact boundary problem EC wave solution again shows that simultaneously is exciting also the O-mode (with smaller amplitude), presumably due to reflection effects and wave depolarization at the wall.

  13. High relaxivity Gd(III)-DNA gold nanostars: investigation of shape effects on proton relaxation.

    PubMed

    Rotz, Matthew W; Culver, Kayla S B; Parigi, Giacomo; MacRenaris, Keith W; Luchinat, Claudio; Odom, Teri W; Meade, Thomas J

    2015-03-24

    Gadolinium(III) nanoconjugate contrast agents (CAs) have distinct advantages over their small-molecule counterparts in magnetic resonance imaging. In addition to increased Gd(III) payload, a significant improvement in proton relaxation efficiency, or relaxivity (r1), is often observed. In this work, we describe the synthesis and characterization of a nanoconjugate CA created by covalent attachment of Gd(III) to thiolated DNA (Gd(III)-DNA), followed by surface conjugation onto gold nanostars (DNA-Gd@stars). These conjugates exhibit remarkable r1 with values up to 98 mM(-1) s(-1). Additionally, DNA-Gd@stars show efficient Gd(III) delivery and biocompatibility in vitro and generate significant contrast enhancement when imaged at 7 T. Using nuclear magnetic relaxation dispersion analysis, we attribute the high performance of the DNA-Gd@stars to an increased contribution of second-sphere relaxivity compared to that of spherical CA equivalents (DNA-Gd@spheres). Importantly, the surface of the gold nanostar contains Gd(III)-DNA in regions of positive, negative, and neutral curvature. We hypothesize that the proton relaxation enhancement observed results from the presence of a unique hydrophilic environment produced by Gd(III)-DNA in these regions, which allows second-sphere water molecules to remain adjacent to Gd(III) ions for up to 10 times longer than diffusion. These results establish that particle shape and second-sphere relaxivity are important considerations in the design of Gd(III) nanoconjugate CAs.

  14. Mode-selective quantization and multimodal effective models for spherically layered systems

    NASA Astrophysics Data System (ADS)

    Dzsotjan, D.; Rousseaux, B.; Jauslin, H. R.; des Francs, G. Colas; Couteau, C.; Guérin, S.

    2016-08-01

    We propose a geometry-specific, mode-selective quantization scheme in coupled field-emitter systems which makes it easy to include material and geometrical properties, and intrinsic losses, as well as the positions of an arbitrary number of quantum emitters. The method is presented through the example of a spherically symmetric, nonmagnetic, arbitrarily layered system. We follow it up by a framework to project the system on simpler, effective cavity QED models. Maintaining a well-defined connection to the original quantization, we derive the emerging effective quantities from the full, mode-selective model in a mathematically consistent way. We discuss the uses and limitations of these effective models.

  15. Effect of laser parameters and mode on pulp surgery outcome

    NASA Astrophysics Data System (ADS)

    Wilder-Smith, Petra B. B.; Arrastia-Jitosho, Anna-Marie A.; Peavy, George M.; Kurosaki, Tom

    1997-05-01

    The objective of this study was to determine the effectiveness of localized laser pulp surgery in the canine model. Effects of laser parameters on treatment outcome were also investigated. Pulpal exposure 3 mm in diameter were prepared in healthy teeth and left open to infection from the oral cavity for 72 hours. Pulpal tissue was then removed using high speed handpiece with sterile irrigation, or a CO2 laser. Teeth were monitored clinically, radiographically for 3 months. Results for each criterion were evaluated on a scale of 0-(-2). After sacrifice, histological assessment was made soft and hard tissue response. Results for each category were evaluated on a standard scale of 0-(-2). All evaluations were performed by 1 blinded, pre-standardized clinician. Statistical assessment using the chi-square test and Fisher's Exact Test associated laser treatment with a significantly better clinical, radiographic and histological treatment outcome. NIH RRO1192, seed grant funding form Loma Linda University, the Edna P. Jacobsen Charitable Trust for Animals, Inc.

  16. Effective action approach and Carlson-Goldman mode in d-wave superconductors

    NASA Astrophysics Data System (ADS)

    Sharapov, Sergei G.; Beck, Hans

    2002-04-01

    We theoretically investigate the Carlson-Goldman (CG) mode in two-dimensional clean d-wave superconductors using the effective ``phase-only'' action formalism. In conventional s-wave superconductors, it is known that the CG mode is observed as a peak in the structure factor of the pair susceptibility S(Ω,K) only just below the transition temperature Tc and only in dirty systems. On the other hand, our analytical results support the statement by Ohashi and Takada [Phys. Rev. B 62, 5971 (2000)] that in d-wave superconductors the CG mode can exist in clean systems down to much lower temperatures, T~0.1Tc. We also consider the manifestations of the CG mode in the density-density and current-current correlators and discuss the gauge independence of the obtained results.

  17. Effects of Spatial Variations in Coronal Electron and Ion Temperatures on Type III Bursts. II. Variations in Ion Temperature

    NASA Astrophysics Data System (ADS)

    Li, B.; Cairns, Iver H.; Robinson, P. A.

    2011-03-01

    Quasilinear-based simulations are presented for the effects on coronal type III bursts of spatially varying ion temperature Ti in the corona. The simulations use a newly developed method for integrating spatial variations of coronal temperatures into our previous simulations for constant temperatures. The effects are simulated for monotonic Ti variations and/or for spatially localized enhancements in Ti . Generally, a localized enhancement in Ti has stronger effects on type III bursts than a corresponding monotonic variation in Ti . A localized Ti enhancement causes modulations to the dynamic spectra of fp and 2fp emission at frequencies corresponding to the disturbance: a narrowband slowly drifting intensification for both fp and 2fp emission and a narrowband suppression for 2fp emission. The fp emission may become observable due to the disturbance, although still much weaker than the 2fp emission. Signatures of the Ti enhancement are found in the 2fp spectral characteristics, e.g., the maximum flux and frequency drift rate. Importantly, these signatures are distinct from those of localized disturbances in electron temperature Te . The results indicate that coronal type III bursts provide a new tool to probe and distinguish localized disturbances in Ti or Te in the corona. Additionally, the presence of multiple spatially confined Ti enhancements at different heights may produce some observed fine structures in type III bursts; e.g., stria bursts and associated flux modulations in type IIIb bursts, and flux modulations in type IIIs whose beams traverse coronal shocks.

  18. Implications of the Differential Toxicological Effects of III-V Ionic and Particulate Materials for Hazard Assessment of Semiconductor Slurries.

    PubMed

    Jiang, Wen; Lin, Sijie; Chang, Chong Hyun; Ji, Zhaoxia; Sun, Bingbing; Wang, Xiang; Li, Ruibin; Pon, Nanetta; Xia, Tian; Nel, André E

    2015-12-22

    Because of tunable band gaps, high carrier mobility, and low-energy consumption rates, III-V materials are attractive for use in semiconductor wafers. However, these wafers require chemical mechanical planarization (CMP) for polishing, which leads to the generation of large quantities of hazardous waste including particulate and ionic III-V debris. Although the toxic effects of micron-sized III-V materials have been studied in vivo, no comprehensive assessment has been undertaken to elucidate the hazardous effects of submicron particulates and released III-V ionic components. Since III-V materials may contribute disproportionately to the hazard of CMP slurries, we obtained GaP, InP, GaAs, and InAs as micron- (0.2-3 μm) and nanoscale (<100 nm) particles for comparative studies of their cytotoxic potential in macrophage (THP-1) and lung epithelial (BEAS-2B) cell lines. We found that nanosized III-V arsenides, including GaAs and InAs, could induce significantly more cytotoxicity over a 24-72 h observation period. In contrast, GaP and InP particulates of all sizes as well as ionic GaCl3 and InCl3 were substantially less hazardous. The principal mechanism of III-V arsenide nanoparticle toxicity is dissolution and shedding of toxic As(III) and, to a lesser extent, As(V) ions. GaAs dissolves in the cell culture medium as well as in acidifying intracellular compartments, while InAs dissolves (more slowly) inside cells. Chelation of released As by 2,3-dimercapto-1-propanesulfonic acid interfered in GaAs toxicity. Collectively, these results demonstrate that III-V arsenides, GaAs and InAs nanoparticles, contribute in a major way to the toxicity of III-V materials that could appear in slurries. This finding is of importance for considering how to deal with the hazard potential of CMP slurries.

  19. Effects of a sheared toroidal rotation on the stability boundary of the MHD modes in the tokamak edge pedestal

    NASA Astrophysics Data System (ADS)

    Aiba, N.; Tokuda, S.; Furukawa, M.; Oyama, N.; Ozeki, T.

    2009-06-01

    Effects of a sheared toroidal rotation are investigated numerically on the stability of the MHD modes in the tokamak edge pedestal, which relate to the type-I edge-localized mode. A linear MHD stability code MINERVA is newly developed for solving the Frieman-Rotenberg equation that is the linear ideal MHD equation with flow. Numerical stability analyses with this code reveal that the sheared toroidal rotation destabilizes edge localized MHD modes for rotation frequencies which are experimentally achievable, though the ballooning mode stability changes little by rotation. This rotation effect on the edge MHD stability becomes stronger as the toroidal mode number of the unstable MHD mode increases when the stability analysis was performed for MHD modes with toroidal mode numbers smaller than 40. The toroidal mode number of the unstable MHD mode depends on the stabilization of the current-driven mode and the ballooning mode by increasing the safety factor. This dependence of the toroidal mode number of the unstable mode on the safety factor is considered to be the reason that the destabilization by toroidal rotation is stronger for smaller edge safety factors.

  20. Observing mesoscale eddy effects on mode-water subduction and transport in the North Pacific.

    PubMed

    Xu, Lixiao; Li, Peiliang; Xie, Shang-Ping; Liu, Qinyu; Liu, Cong; Gao, Wendian

    2016-02-01

    While modelling studies suggest that mesoscale eddies strengthen the subduction of mode waters, this eddy effect has never been observed in the field. Here we report results from a field campaign from March 2014 that captured the eddy effects on mode-water subduction south of the Kuroshio Extension east of Japan. The experiment deployed 17 Argo floats in an anticyclonic eddy (AC) with enhanced daily sampling. Analysis of over 3,000 hydrographic profiles following the AC reveals that potential vorticity and apparent oxygen utilization distributions are asymmetric outside the AC core, with enhanced subduction near the southeastern rim of the AC. There, the southward eddy flow advects newly ventilated mode water from the north into the main thermocline. Our results show that subduction by eddy lateral advection is comparable in magnitude to that by the mean flow--an effect that needs to be better represented in climate models.

  1. Nonlinear dynamics of the tearing mode with two-fluid and curvature effects in tokamaks

    SciTech Connect

    Meshcheriakov, Dmytro; Maget, Patrick; Garbet, Xavier; Lütjens, Hinrich; Beyer, Peter

    2014-01-15

    Curvature and diamagnetic effects are both known to have an influence on tearing mode dynamics. In this paper, we investigate the impact of these effects on the nonlinear stability and saturation of a (2, 1) island using non-linear two-fluid MHD simulations and we apply our results to Tore Supra experiments, where its behavior is not well understood from the single fluid MHD model. Simulations show that a metastable state induced by diamagnetic effect exists for this mode and that it also produces a reduction of the saturated island size, in presence of toroidal curvature. The mode is found to be nonlinearly destabilized by a seed island and it saturates at a macroscopic level causing a significant confinement degradation. The interpretation of dual states, with either no island on q = 2 or a large one, observed on discharges with high non inductive current source on Tore Supra, is revisited.

  2. Observing mesoscale eddy effects on mode-water subduction and transport in the North Pacific

    PubMed Central

    Xu, Lixiao; Li, Peiliang; Xie, Shang-Ping; Liu, Qinyu; Liu, Cong; Gao, Wendian

    2016-01-01

    While modelling studies suggest that mesoscale eddies strengthen the subduction of mode waters, this eddy effect has never been observed in the field. Here we report results from a field campaign from March 2014 that captured the eddy effects on mode-water subduction south of the Kuroshio Extension east of Japan. The experiment deployed 17 Argo floats in an anticyclonic eddy (AC) with enhanced daily sampling. Analysis of over 3,000 hydrographic profiles following the AC reveals that potential vorticity and apparent oxygen utilization distributions are asymmetric outside the AC core, with enhanced subduction near the southeastern rim of the AC. There, the southward eddy flow advects newly ventilated mode water from the north into the main thermocline. Our results show that subduction by eddy lateral advection is comparable in magnitude to that by the mean flow—an effect that needs to be better represented in climate models. PMID:26829888

  3. The effect of an anisotropic pressure of thermal particles on resistive wall mode stability

    SciTech Connect

    Berkery, J. W. Sabbagh, S. A.; Betti, R.; Guazzotto, L.; Manickam, J.

    2014-11-15

    The effect of an anisotropic pressure of thermal particles on resistive wall mode stability in tokamak fusion plasmas is derived through kinetic theory and assessed through calculation with the MISK code [B. Hu et al., Phys. Plasmas 12, 0 57301 (2005)]. The fluid anisotropy is treated as a small perturbation on the plasma equilibrium and modeled with a bi-Maxwellian distribution function. A complete stability treatment without an assumption of high frequency mode rotation leads to anisotropic kinetic terms in the dispersion relation in addition to anisotropy corrections to the fluid terms. With the density and the average pressure kept constant, when thermal particles have a higher temperature perpendicular to the magnetic field than parallel, the fluid pressure-driven ballooning destabilization term is reduced. Additionally, the stabilizing kinetic effects of the trapped thermal ions can be enhanced. Together these two effects can lead to a modest increase in resistive wall mode stability.

  4. BEIR-III report and the health effects of low-level radiation

    SciTech Connect

    Fabrikant, J.I.

    1980-01-01

    The present BEIR-III Committee has not highlighted any controversy over the health effects of low-level radiation. In its evaluation of the experimental data and epidemiological surveys, the Committee has carefully reviewed and assessed the value of all the available scientific evidence for estimating numerical risk coefficients for the health hazards to human populations exposed to low levels of ionizing radiation. Responsible public awareness of the possible health effects of ionizing radiations from medical and industrial radiation exposure, centers on three important matters of societal concern: (1) to place into perspective the extent of harm to the health of man and his descendants to be expected in the present and in the future from those societal activities involving ionizing radiation; (2) to develop quantitative indices of harm based on dose-effect relationships; such indices could then be used with prudent caution to introduce concepts of the regulation of population doses on the basis of somatic and genetic risks; and (3) to identify the magnitude and extent of radiation activities which could cause harm, to assess their relative significance, and to provide a framework for recommendations on how to reduce unnecessary radiation exposure to human populations. The main difference of the BEIR Committee Report is not so much from new data or new interpretations of existing data, but rather from a philosophical approach and appraisal of existing and future radiation protection resulting from an atmosphere of constantly changing societal conditions and public attitudes. (PCS)

  5. Explanation of non-additive effects in mixtures of similar mode of action chemicals.

    PubMed

    Kamo, Masashi; Yokomizo, Hiroyuki

    2015-09-01

    Many models have been developed to predict the combined effect of drugs and chemicals. Most models are classified into two additive models: independent action (IA) and concentration addition (CA). It is generally considered if the modes of action of chemicals are similar then the combined effect obeys CA; however, many empirical studies report nonlinear effects deviating from the predictions by CA. Such deviations are termed synergism and antagonism. Synergism, which leads to a stronger toxicity, requires more careful management, and hence it is important to understand how and which combinations of chemicals lead to synergism. In this paper, three types of chemical reactions are mathematically modeled and the cause of the nonlinear effects among chemicals with similar modes of action was investigated. Our results show that combined effects obey CA only when the modes of action are exactly the same. Contrary to existing knowledge, combined effects are generally nonlinear even if the modes of action of the chemicals are similar. Our results further show that the nonlinear effects vanish out when the chemical concentrations are low, suggesting that the current management procedure of assuming CA is rarely inappropriate because environmental concentrations of chemicals are generally low.

  6. Dentofacial effects of bone-anchored maxillary protraction: A controlled study of consecutively treated Class III patients

    PubMed Central

    De Clerck, Hugo; Cevidanes, Lucia; Baccetti, Tiziano

    2011-01-01

    Introduction In this cephalometric investigation, we analyzed the treatment effects of bone-anchored maxillary protraction (BAMP) with miniplates in the maxilla and mandible connected by Class III elastics in patients with Class III malocclusion. Methods The treated sample consisted of 21 Class III patients consecutively treated with the BAMP protocol before the pubertal growth spurt (mean age, 11.10 ± 1.8 years) and reevaluated after BAMP therapy, about 1 year later. The treated group was compared with a matched control group of 18 untreated Class III subjects. Significant differences between the treated and control groups were assessed with independent-sample t tests (P<0.05). Results Sagittal measurements of the maxilla showed highly significant improvements during active treatment (about 4 mm more than the untreated controls), with significant protraction effects at orbitale and pterygomaxillare. Significant improvements of overjet and molar relationship were recorded, as well as in the mandibular skeletal measures at Point B and pogonion. Vertical skeletal changes and modifications in incisor inclination were negligible, except for a significant proclination of the mandibular incisors in the treated group. Significant soft-tissue changes reflected the underlying skeletal modifications. Conclusions Compared with growth of the untreated Class III subjects, the BAMP protocol induced an average increment on skeletal and soft-tissue advancement of maxillary structures of about 4 mm, and favorable mandibular changes exceeded 2 mm. PMID:21055597

  7. The effects of NSAIDs on types I, II, and III collagen metabolism in a rat osteoarthritis model.

    PubMed

    Ou, Yun-Sheng; Tan, Chao; An, Hong; Jiang, Dian-Ming; Quan, Zheng-Xue; Tang, Ke; Luo, Xiao-Ji

    2012-08-01

    The effects of long-term use of celecoxib, ibuprofen, and indomethacin on types I, II, and III collagen metabolism were evaluated in rat osteoarthritis (OA) model. One hundred and thirty wistar rats were randomly divided into 4 groups: the celecoxib group, the ibuprofen group, the indomethacin group, and the normal saline group. The osteoarthritis was induced by the excision of the left Achilles tendon. In the 3rd, 6th, and 9th month of treatment after surgically induced osteoarthritis, the articular cartilage was observed with microscope using HE staining. The expression of proteoglycans was semiquantified using toluidine blue staining. And, the expressions of types I, II, and III collagen in chondrocytes were examined using immunohistochemistry. The results suggested that celecoxib had no remarkable effects on the expression of types I, II, and III collagen. Ibuprofen upgraded the expression of types I, II, and III collagen and increased the synthesis of collagen. Indomethacin suppressed the expression of type II collagen and enhanced the expression of types I and III collagen. Therefore, during the long-term use of NSAIDs in osteoarthritis, celecoxib may have no remarkable influences on collagen metabolism of the articular cartilage and may be the ideal choice in the treatment of chronic destructive joint disease when anti-inflammatory drugs need to be used for a prolonged period. Ibuprofen may be unfavorable, and indomethacin may be harmful to collagen metabolism in OA treatment.

  8. Sludge-Derived Biochar for Arsenic(III) Immobilization: Effects of Solution Chemistry on Sorption Behavior.

    PubMed

    Zhang, Weihua; Zheng, Juan; Zheng, Pingping; Tsang, Daniel C W; Qiu, Rongliang

    2015-07-01

    Recycling sewage sludge by pyrolysis has attracted increasing attention for pollutant removal from wastewater and soils. This study scrutinized As(III) sorption behavior on sludge-derived biochar (SDBC) under different pyrolysis conditions and solution chemistry. The SDBC pyrolyzed at a higher temperature showed a lower As(III) sorption capacity and increasingly nonlinear isotherm due to loss of surface sites and deoxygenation-dehydrogenation. The Langmuir sorption capacity on SDBC (3.08-6.04 mg g) was comparable to other waste-derived sorbents, with the highest As(III) sorption on SDBC pyrolyzed at 400°C for 2 h. The As(III) sorption kinetics best fit with the pseudo-second-order equation, thus suggesting the significance of the availability of surface sites and initial concentration. Sorption of As(III) was faster than that of Cr(VI) but slower than that of Pb(II), which was attributed to their differences in molar volume (correlated to diffusion coefficients) and sorption mechanisms. The X-ray photoelectron spectra revealed an increase of oxide oxygen (O) with a decrease of sorbed water, indicative of ligand exchange with hydroxyl groups on SDBC surfaces. The As(III) sorption was not pH dependent in acidic-neutral range (pH < 8) due to the buffering capacity and surface characteristics of the SDBC; however, sorption was promoted by increasing pH in the alkaline range (pH > 8) because of As(III) speciation in solution. An increasing ionic strength (0.001-0.1 mol L) facilitated As(III) sorption, indicating the predominance of ligand exchange over electrostatic interactions, while high concentrations (0.1 mol L) of competing anions (fluoride, sulfate, carbonate, and phosphate) inhibited As(III) sorption. These results suggest that SDBC is applicable for As(III) immobilization in most environmentally relevant conditions. PMID:26437093

  9. Atom-mediated effective interactions between modes of a bimodal cavity

    SciTech Connect

    Prado, F. O.; Luiz, F. S.; Villas-Boas, J. M.; Alcalde, A. M.; Duzzioni, E. I.; Sanz, L.

    2011-11-15

    We show a procedure for engineering effective interactions between two modes in a bimodal cavity. Our system consists of one or more two-level atoms, excited by a classical field, interacting with both modes. The two effective Hamiltonians have forms similar to beam-splitter and quadratic beam-splitter interactions. We also demonstrate that the nonlinear Hamiltonian can be used to prepare an entangled coherent state, also known as a multidimensional entangled coherent state, which has been pointed out as an important entanglement resource. We show that the nonlinear interaction parameter can be enhanced considering N independent atoms trapped inside a high-finesse optical cavity.

  10. Effects of normal mode loss in dielectric waveguide directional couplers and interferometers

    NASA Astrophysics Data System (ADS)

    Youngquist, R. C.; Stokes, L. F.; Shaw, H. J.

    1983-12-01

    Theoretical arguments and experimental evidence are presented to show that the two fundamental normal modes of a coupled waveguide structure have different attenuations in traversing such a structure. The effects of this phenomenon on evanescent wave directional counters and interferometers are derived. Parasitic effects in Mach-Zehnder and Sagnac interferometers utilizing directional couplers are described. An asymmetric output for the recently demonstrated all-single-mode fiber resonator is predicted and compared to experimental results. Some qualitative results are presented for integrated optic directional coupler switches.

  11. Application of failure mode and effect analysis in an assisted reproduction technology laboratory.

    PubMed

    Intra, Giulia; Alteri, Alessandra; Corti, Laura; Rabellotti, Elisa; Papaleo, Enrico; Restelli, Liliana; Biondo, Stefania; Garancini, Maria Paola; Candiani, Massimo; Viganò, Paola

    2016-08-01

    Assisted reproduction technology laboratories have a very high degree of complexity. Mismatches of gametes or embryos can occur, with catastrophic consequences for patients. To minimize the risk of error, a multi-institutional working group applied failure mode and effects analysis (FMEA) to each critical activity/step as a method of risk assessment. This analysis led to the identification of the potential failure modes, together with their causes and effects, using the risk priority number (RPN) scoring system. In total, 11 individual steps and 68 different potential failure modes were identified. The highest ranked failure modes, with an RPN score of 25, encompassed 17 failures and pertained to "patient mismatch" and "biological sample mismatch". The maximum reduction in risk, with RPN reduced from 25 to 5, was mostly related to the introduction of witnessing. The critical failure modes in sample processing were improved by 50% in the RPN by focusing on staff training. Three indicators of FMEA success, based on technical skill, competence and traceability, have been evaluated after FMEA implementation. Witnessing by a second human operator should be introduced in the laboratory to avoid sample mix-ups. These findings confirm that FMEA can effectively reduce errors in assisted reproduction technology laboratories.

  12. Application of failure mode and effect analysis in an assisted reproduction technology laboratory.

    PubMed

    Intra, Giulia; Alteri, Alessandra; Corti, Laura; Rabellotti, Elisa; Papaleo, Enrico; Restelli, Liliana; Biondo, Stefania; Garancini, Maria Paola; Candiani, Massimo; Viganò, Paola

    2016-08-01

    Assisted reproduction technology laboratories have a very high degree of complexity. Mismatches of gametes or embryos can occur, with catastrophic consequences for patients. To minimize the risk of error, a multi-institutional working group applied failure mode and effects analysis (FMEA) to each critical activity/step as a method of risk assessment. This analysis led to the identification of the potential failure modes, together with their causes and effects, using the risk priority number (RPN) scoring system. In total, 11 individual steps and 68 different potential failure modes were identified. The highest ranked failure modes, with an RPN score of 25, encompassed 17 failures and pertained to "patient mismatch" and "biological sample mismatch". The maximum reduction in risk, with RPN reduced from 25 to 5, was mostly related to the introduction of witnessing. The critical failure modes in sample processing were improved by 50% in the RPN by focusing on staff training. Three indicators of FMEA success, based on technical skill, competence and traceability, have been evaluated after FMEA implementation. Witnessing by a second human operator should be introduced in the laboratory to avoid sample mix-ups. These findings confirm that FMEA can effectively reduce errors in assisted reproduction technology laboratories. PMID:27282213

  13. Effects of load voltage on voltage breakdown modes of electrical exploding aluminum wires in air

    NASA Astrophysics Data System (ADS)

    Wu, Jian; Li, Xingwen; Yang, Zefeng; Wang, Kun; Chao, Youchuang; Shi, Zongqian; Jia, Shenli; Qiu, Aici

    2015-06-01

    The effects of the load voltage on the breakdown modes are investigated in exploding aluminum wires driven by a 1 kA, 0.1 kA/ns pulsed current in air. From laser probing images taken by laser shadowgraphy, schlieren imaging, and interferometry, the position of the shockwave front, the plasma channel, and the wire core edge of the exploding product can be determined. The breakdown mode makes a transition from the internal mode, which involves breakdown inside the wire core, to the shunting mode, which involves breakdown in the compressed air, with decreasing charging voltage. The breakdown electrical field for a gaseous aluminum wire core of nearly solid density is estimated to be more than 20 kV/cm, while the value for gaseous aluminum of approximately 0.2% solid density decreases to 15-20 kV/cm. The breakdown field in shunting mode is less than 20 kV/cm and is strongly affected by the vaporized aluminum, the desorbed gas, and the electrons emitted from the wire core during the current pause. Ohmic heating during voltage collapses will induce further energy deposition in the current channel and thus will result in different expansion speeds for both the wire core and the shockwave front in the different modes.

  14. Effects of load voltage on voltage breakdown modes of electrical exploding aluminum wires in air

    SciTech Connect

    Wu, Jian; Li, Xingwen Yang, Zefeng; Wang, Kun; Chao, Youchuang; Shi, Zongqian; Jia, Shenli; Qiu, Aici

    2015-06-15

    The effects of the load voltage on the breakdown modes are investigated in exploding aluminum wires driven by a 1 kA, 0.1 kA/ns pulsed current in air. From laser probing images taken by laser shadowgraphy, schlieren imaging, and interferometry, the position of the shockwave front, the plasma channel, and the wire core edge of the exploding product can be determined. The breakdown mode makes a transition from the internal mode, which involves breakdown inside the wire core, to the shunting mode, which involves breakdown in the compressed air, with decreasing charging voltage. The breakdown electrical field for a gaseous aluminum wire core of nearly solid density is estimated to be more than 20 kV/cm, while the value for gaseous aluminum of approximately 0.2% solid density decreases to 15–20 kV/cm. The breakdown field in shunting mode is less than 20 kV/cm and is strongly affected by the vaporized aluminum, the desorbed gas, and the electrons emitted from the wire core during the current pause. Ohmic heating during voltage collapses will induce further energy deposition in the current channel and thus will result in different expansion speeds for both the wire core and the shockwave front in the different modes.

  15. On the interplay effects with proton scanning beams in stage III lung cancer

    SciTech Connect

    Li, Yupeng; Kardar, Laleh; Liao, Li; Lim, Gino; Li, Xiaoqiang; Li, Heng; Zhu, Ronald X.; Sahoo, Narayan; Gillin, Michael; Zhang, Xiaodong; Cao, Wenhua; Chang, Joe Y.; Liao, Zhongxing; Komaki, Ritsuko; Cox, James D.

    2014-02-15

    Purpose: To assess the dosimetric impact of interplay between spot-scanning proton beam and respiratory motion in intensity-modulated proton therapy (IMPT) for stage III lung cancer. Methods: Eleven patients were sampled from 112 patients with stage III nonsmall cell lung cancer to well represent the distribution of 112 patients in terms of target size and motion. Clinical target volumes (CTVs) and planning target volumes (PTVs) were defined according to the authors' clinical protocol. Uniform and realistic breathing patterns were considered along with regular- and hypofractionation scenarios. The dose contributed by a spot was fully calculated on the computed tomography (CT) images corresponding to the respiratory phase that the spot is delivered, and then accumulated to the reference phase of the 4DCT to generate the dynamic dose that provides an estimation of what might be delivered under the influence of interplay effect. The dynamic dose distributions at different numbers of fractions were compared with the corresponding 4D composite dose which is the equally weighted average of the doses, respectively, computed on respiratory phases of a 4DCT image set. Results: Under regular fractionation, the average and maximum differences in CTV coverage between the 4D composite and dynamic doses after delivery of all 35 fractions were no more than 0.2% and 0.9%, respectively. The maximum differences between the two dose distributions for the maximum dose to the spinal cord, heart V40, esophagus V55, and lung V20 were 1.2 Gy, 0.1%, 0.8%, and 0.4%, respectively. Although relatively large differences in single fraction, correlated with small CTVs relative to motions, were observed, the authors' biological response calculations suggested that this interfractional dose variation may have limited biological impact. Assuming a hypofractionation scenario, the differences between the 4D composite and dynamic doses were well confined even for single fraction. Conclusions: Despite

  16. Where is the breathing mode? High voltage Hall effect thruster studies with EMD method

    SciTech Connect

    Kurzyna, J.; Makowski, K.; Mazouffre, S.; Peradzynski, Z.; Lazurenko, A.; Dudeck, M.

    2008-03-19

    Discharge current and local plasma oscillations are studied in a high voltage Hall effect thruster PPS registered -X000. Characteristic time scales that appear in different operating conditions are resolved with the use of Hilbert-Huang spectra (HHS) which display time dependenc of instantaneous frequency and power. Sets of intrinsic mode functions (imfs) that are used for HHS calculation result due to application of empirical mode decomposition method (EMD) to nonstationary multicomponent signals. In the experiment the signals are captured in the electric circuit of the thruster as well locally, in the vicinity of the thruster exhaust region. Classical electric probes spaced along the azimuth and/or thruster axis let us study correlations of signals which were captured in different locations. In this way azimuthal and axial propagation of disturbances is inspected. The discharge voltage is varied in the range of 200 divide 900 V while xenon mas flow rate of 5 divide 9 mg/s. LF, MF, and HF characteristic bands that are known from previous studies of PPS registered -100 thruster have been also detected here. However, expanding discharge current onto a set of intrinsic modes we can resolve MF mode more reliably than before. Moreover, for higher discharge voltages, this irregular mode turns into more regular waveform and tends to dominate in the discharge current masking almost completely the breathing mode (LF oscillations of the discharge current). In such a case triggering of HF oscillations is correlated with the phase of MF mode while in the case of PPS registered -100 thruster it was correlated with the appropriate phase of the breathing mode (LF band). Regular HF emission that can be unambiguously interpreted as azimuthal electrostatic wave now is observed only in the specific operating conditions of the thruster. However, even if irregular HF emission is observed the time delay of cross-correlated signals which are captured in different azimuthal locations

  17. Bismuth(III) deferiprone effectively inhibits growth of Desulfovibrio desulfuricans ATCC 27774.

    PubMed

    Barton, Larry L; Lyle, Daniel A; Ritz, Nathaniel L; Granat, Alex S; Khurshid, Ali N; Kherbik, Nada; Hider, Robert; Lin, Henry C

    2016-04-01

    Sulfate-reducing bacteria have been implicated in inflammatory bowel diseases and ulcerative colitis in humans and there is an interest in inhibiting the growth of these sulfide-producing bacteria. This research explores the use of several chelators of bismuth to determine the most effective chelator to inhibit the growth of sulfate-reducing bacteria. For our studies, Desulfovibrio desulfuricans ATCC 27774 was grown with nitrate as the electron acceptor and chelated bismuth compounds were added to test for inhibition of growth. Varying levels of inhibition were attributed to bismuth chelated with subsalicylate or citrate but the most effective inhibition of growth by D. desulfuricans was with bismuth chelated by deferiprone, 3-hydroxy-1,2-dimethyl-4(1H)-pyridone. Growth of D. desulfuricans was inhibited by 10 μM bismuth as deferiprone:bismuth with either nitrate or sulfate respiration. Our studies indicate deferiprone:bismuth has bacteriostatic activity on D. desulfuricans because the inhibition can be reversed following exposure to 1 mM bismuth for 1 h at 32 °C. We suggest that deferiprone is an appropriate chelator for bismuth to control growth of sulfate-reducing bacteria because deferiprone is relatively nontoxic to animals, including humans, and has been used for many years to bind Fe(III) in the treatment of β-thalassemia. PMID:26896170

  18. Birefringence effects in multi-core fiber: coupled local-mode theory.

    PubMed

    Macho, Andrés; García-Meca, Carlos; Fraile-Peláez, F Javier; Morant, Maria; Llorente, Roberto

    2016-09-19

    In this paper, we evaluate experimentally and model theoretically the intra- and inter-core crosstalk between the polarized core modes in single-mode multi-core fiber media including temporal and longitudinal birefringent effects. Specifically, extensive experimental results on a four-core fiber indicate that the temporal fluctuation of fiber birefringence modifies the intra- and inter-core crosstalk behavior in both linear and nonlinear optical power regimes. To gain theoretical insight into the experimental results, we introduce an accurate multi-core fiber model based on local modes and perturbation theory, which is derived from the Maxwell equations including both longitudinal and temporal birefringent effects. Numerical calculations based on the developed theory are found to be in good agreement with the experimental data. PMID:27661883

  19. Optical and mechanical mode tuning in an optomechanical crystal with light-induced thermal effects

    SciTech Connect

    Navarro-Urrios, D.; Gomis-Bresco, J.; Alzina, F.; Capuj, N. E.; Griol, A.; Puerto, D.; Martínez, A.; Sotomayor-Torres, C. M.

    2014-09-07

    We report on the modification of the optical and mechanical properties of a silicon 1D optomechanical crystal cavity due to thermo-optic effects in a high phonon/photon population regime. The cavity heats up due to light absorption in a way that shifts the optical modes towards longer wavelengths and the mechanical modes to lower frequencies. By combining the experimental optical results with finite-difference time-domain simulations, we establish a direct relation between the observed wavelength drift and the actual effective temperature increase of the cavity. By assuming that the Young's modulus decreases accordingly to the temperature increase, we find a good agreement between the mechanical mode drift predicted using a finite element method and the experimental one.

  20. The effect of truncating the normal mode coupling equations on synthetic spectra

    NASA Astrophysics Data System (ADS)

    Akbarashrafi, F.; Valentine, A. P.; Al-Attar, D.; Trampert, J.

    2015-12-01

    The free oscillations, or normal modes, of the Earth provide important constraints on the long-wavelength structure of our planet. Calculations using normal modes are also necessary if the effects of gravity are to be fully modeled in seismic waveforms, which becomes important at low frequencies. To implement these calculations, we typically initially compute the normal modes (eigenfunctions) of a spherically-symmetric model such as PREM. These form a complete set of basis functions, which may then be used to describe the seismic response of laterally heterogeneous models. This procedure is known as 'mode coupling'. In order to implement the calculation, it is necessary to select a finite subset of modes (invariably defined by a frequency range) to be considered. This truncation of the infinite-dimensional equations necessarily introduces an error into the results. Here, we consider the fundamental question: if we wish to calculate synthetic spectra in a given frequency range, how many modes must we couple for the resulting spectra to be sufficiently accurate? To investigate this question, we compute spectra in the 3D model S20RTS up to 2mHz, but allowing coupling with all modes up to 5mHz. We then explore how the spectra change as we reduce the upper frequency used in the coupling. We compare this to the effects introduced by altering the 3D density structure of the model. Clearly, if we wish to image Earth's density structure accurately, it is important that the truncation error is small compared to this signal.

  1. Effectiveness and cost of failure mode and effects analysis methodology to reduce neurosurgical site infections.

    PubMed

    Hover, Alexander R; Sistrunk, William W; Cavagnol, Robert M; Scarrow, Alan; Finley, Phillip J; Kroencke, Audrey D; Walker, Judith L

    2014-01-01

    Mercy Hospital Springfield is a tertiary care facility with 32 000 discharges and 15 000 inpatient surgeries in 2011. From June 2009 through January 2011, a stable inpatient elective neurosurgery infection rate of 2.15% was observed. The failure mode and effects analysis (FMEA) methodology to reduce inpatient neurosurgery infections was utilized. Following FMEA implementation, overall elective neurosurgery infection rates were reduced to 1.51% and sustained through May 2012. Compared with baseline, the post-FMEA deep-space and organ infection rate was reduced by 41% (P = .052). Overall hospital inpatient clean surgery infection rates for the same time frame did not decrease to the same extent, suggesting a specific effect of the FMEA. The study team believes that the FMEA interventions resulted in 14 fewer expected infections, $270 270 in savings, a 168-day reduction in expected length of stay, and 22 fewer readmissions. Given the serious morbidity and cost of health care-associated infections, the study team concludes that FMEA implementation was clinically cost-effective.

  2. Hybrid simulation of energetic particle effects on tearing modes in tokamak plasmas

    SciTech Connect

    Cai Huishan; Fu Guoyong

    2012-07-15

    The effects of energetic ions on stability of tearing mode are investigated by global kinetic/MHD hybrid simulations in a low beta tokamak plasma. The kinetic effects of counter circulating energetic ions from the non-adiabatic response are found to be strongly destabilizing while the effects from the adiabatic response are stabilizing. The net effect with both adiabatic and non-adiabatic contributions is destabilizing. On the other hand, the kinetic effects of co-circulating energetic ions from the non-adiabatic response are calculated to be weakly stabilizing while the corresponding adiabatic contribution is destabilizing for small energetic ion beta. The net effect is weakly stabilizing. The dependence of kinetic effects on energetic ion beta, gyroradius, and speed is studied systematically and the results agree in large part with the previous analytic results for the kinetic effects of circulating particles. For trapped energetic ions, their effects on tearing mode stability are dominated by the adiabatic response due to large banana orbit width and strong poloidal variation of particle pressure. The net effect of trapped energetic particles on tearing modes is much more destabilizing as compared to that of counter circulating particles at the same beta value.

  3. Interaction of locust apolipophorin III with lipoproteins and phospholipid vesicles: effect of glycosylation.

    PubMed

    Weers, P M; Van Der Horst, D J; Ryan, R O

    2000-03-01

    Apolipophorin III (apoLp-III) from Locusta migratoria is an exchangeable apolipoprotein that binds reversibly to lipoprotein surfaces. The native protein is glycosylated at Asn-18 and Asn-85. Variable attachment of five distinct oligosaccharide moieties at the two glycosylation sites results in molecular weight heterogeneity, as seen by mass spectrometry. The main mass peak of 20,488 Da decreases to 17,583 Da after removal of carbohydrate, indicating that apoLp-III carbohydrate mass is approximately 14% by weight. Deglycosylated apoLp-III induced clearance of dimyristoylphosphatidylcholine and dimyristoylphosphatidylglycerol vesicles at a faster rate than glycosylated apoLp-III. However, in lipoprotein binding assays, in which apoLp-III interacts with surface-localized diacylglycerol, only minor differences in binding were observed. The fluorescence properties of 1-anilinonaphthalene-8-sulfonate were unaffected by the glycosylation state of apoLp-III, indicating that no changes in the relative amount of exposed hydrophobic surface occurred as a result of carbohydrate removal. We propose that glycosyl moieties affect the ability of apoLp-III to transform phospholipid bilayer vesicles into disc-like complexes by steric hindrance. This is due to the requirement that apoLp-III penetrate the bilayer substrate prior to conformational opening of the helix bundle. On the other hand, the glycosyl moieties do not affect lipoprotein binding interactions as it does not involve deep protein penetration into the lipid milieu. Rather, lipoprotein binding is based on oriented protein contact with the lipid surface followed by opening of the helix bundle, which allows formation of a stable interaction with surface exposed hydrophobic sites. PMID:10706589

  4. Ultrafiltration of wastewater: effects of particles, mode of operation, and backwash effectiveness.

    PubMed

    Bourgeous, K N; Darby, J L; Tchobanoglous, G

    2001-01-01

    The effects that wastewater quality and mode of operation have on the performance of an asymmetric, hollow fiber, polysulfone, ultrafiltration (UF) membrane with a molecular weight cutoff of 100,000 Daltons were investigated. Performance was assessed through monitoring membrane flux, transmembrane pressure, effluent biochemical oxygen demand, and operational cost of the experimental system while treating filtered secondary, secondary, and filtered primary effluents. Fluxes achieved for filtered secondary (129-173 l/m2 h), secondary (101-158 l/m2 h), and filtered primary (20-41 l/m2 h) effluents were compared to those obtained at three other locations where similar UF systems were operated. A conceptual model of the impact of an insufficient backwash and of operating the UF system at constant flux on membrane performance is presented to explain the differences in fluxes. Employing pre-membrane granular filtration to remove a portion of the problematic particles in secondary effluent prior to UF led to optimal operational conditions. The costs associated with the operation of pre-membrane granular filtration were offset by the increase in production achieved. Although the use of recirculation could increase maintainable flux when treating a concentrated feed (e.g., filtered primary effluent), the associated costs were high. Improved UF performance was found to result from allowing flux to decline naturally, rather than using a constant flux mode of operation. The effluents produced when filtered secondary and secondary effluents were the feeds would be equivalent to an oxidized, coagulated, clarified, and filtered wastewater as per Title 22 California Wastewater Reclamation Criteria. PMID:11257896

  5. Techniques for setting modes of thermal and deformation effect at combined hardening and finishing operations

    NASA Astrophysics Data System (ADS)

    Rakhimyanov, Kh M.; Rakhimyanov, K. Kh; Rakhimyanov, A. Kh; Kutyshkin, A. V.

    2016-04-01

    This paper considers the issues of setting the modes of thermal and deformation effects in the basic schemes at combined hardening and finishing operations. On the basis of solving the thermal physical problem of material high rate heating, the parameters of a thermohardened layer were determined within the range of the investigated modes. An algorithm for setting the mode parameters of high rate heating responsible for the hardening effect at the combined processing was proposed. The analysis of the mathematical model for forming a surface microrelief at ultrasonic deformation showed that the sizes, the form of fragments and the density of a microrelief were determined by the processing kinematic parameters. An algorithm for setting the rotation speed and feeding at ultrasonic deformation according to microrelief characteristics was developed. The conditions to form a completely regular microrelief on the processed surface that represent the ratio between a single imprint diameter at the ultrasonic deformation and the processing kinematic parameters were determined. The complex of the algorithms suggested for setting the mode parameters of high rate heating and ultrasonic deformation constitutes the techniques for setting the modes of combined hardening and finishing operations.

  6. Altered effective connectivity patterns of the default mode network in Alzheimer's disease: an fMRI study.

    PubMed

    Zhong, Yufang; Huang, Liyu; Cai, Suping; Zhang, Yun; von Deneen, Karen M; Ren, Aifeng; Ren, Junchan

    2014-08-22

    The aim of this work is to investigate the differences of effective connectivity of the default mode network (DMN) in Alzheimer's disease (AD) patients and normal controls (NC). The technique of independent component analysis (ICA) was applied to identify DMN components and multivariate Granger causality analysis (mGCA) was used to explore an effective connectivity pattern. We found that: (i) connections in AD were decreased than those in NC, in terms of intensity and quantity. Posterior cingulated cortex (PCC) exhibited significant activity in NC as it connected with most of the other regions within the DMN. Besides, the PCC was the convergence center which only received interactions from other regions; (ii) right inferior temporal cortex (rITC) in the NC exhibited stronger interactions with other regions within the DMN compared with AD patients; and (iii) interactions between medial prefrontal cortex (MPFC) and bilateral inferior parietal cortex (IPC) in the NC were weaker than those in AD patients. These findings may implicate a brain dysfunction in AD patients and reveal more pathophysiological characteristics of AD.

  7. Ionic Strength Effect on the Rate of Reduction of Hexacyanoferrate (III) by Ascorbic Acid: A Physical Chemistry Laboratory Experiment.

    ERIC Educational Resources Information Center

    Watkins, Kenneth W.; Olson, June A.

    1980-01-01

    Describes a physical chemistry experiment that allows students to test the effect of ionic strength on the rates of a reaction between ions. The reduction of hexacyanoferrate III by ascorbic acid is detailed. Comparisons with the iodine clock reaction are made. (CS)

  8. Tetranuclear hetero-metal [Co(II)2Ln(III)2] (Ln = Gd, Tb, Dy, Ho, La) complexes involving carboxylato bridges in a rare μ4-η(2):η(2) mode: synthesis, crystal structures, and magnetic properties.

    PubMed

    Abtab, Sk Md Towsif; Majee, Mithun Chandra; Maity, Manoranjan; Titiš, Ján; Boča, Roman; Chaudhury, Muktimoy

    2014-02-01

    A new family of 3d-4f heterometal 2 × 2 complexes [Co(II)2(L)2(PhCOO)2Ln(III)2(hfac)4] (1-5) (Ln = Gd (compound 1), Tb (compound 2), Dy (compound 3), Ho (compound 4), and La (compound 5)) have been synthesized in moderate yields (48-63%) following a single-pot protocol using stoichiometric amounts (1:1 mol ratio) of [Co(II)(H2L)(PhCOO)2] (H2L = N,N'-dimethyl-N,N'-bis(2-hydroxy-3,5-dimethylbenzyl)ethylenediamine) as a metalloligand and [Ln(III)(hfac)3(H2O)2] (Hhfac = hexafluoroacetylacetone) as a lanthanide precursor compound. Also reported with this series is the Zn-Dy analog [Zn(II)2(L)2(PhCOO)2Dy(III)2(hfac)4] 6 to help us in understanding the magnetic properties of these compounds. The compounds 1-6 are isostructural. Both hexafluoroacetylacetonate and benzoate play crucial roles in these structures as coligands in generating a tetranuclear core of high thermodynamic stability through a self-assembly process. The metal centers are arranged alternately at the four corners of this rhombic core, and the carboxylato oxygen atoms of each benzoate moiety bind all of the four metal centers of this core in a rare μ4-η(2):η(2) bridging mode as confirmed by X-ray crystallography. The magnetic susceptibility and magnetization data confirm a paramagnetic behavior, and no remnant magnetization exists in any of these compounds at vanishing magnetic field. The metal centers are coupled in an antiferromagnetic manner in these compounds. The [Co(II)2Dy(III)2] compound exhibits a slow magnetic relaxation below 6 K, as proven by the AC susceptibility measurements; the activation energy reads U/kB = 8.8 K (τ0 = 2.0 × 10(-7) s) at BDC = 0, and U/kB = 7.8 K (τ0 = 3.9 × 10(-7) s) at BDC = 0.1 T. The [Zn(II)2Dy(III)2] compound also behaves as a single-molecule magnet with U/kB = 47.9 K and τ0 = 2.75 × 10(-7) s.

  9. Effects of impedance matching network on the discharge mode transitions in a radio-frequency inductively coupled plasma

    SciTech Connect

    Ding, Z. F.; Yuan, G. Y.; Gao, W.; Sun, J. C.

    2008-06-15

    In inductively coupled plasma sources, discharge transitions from electrostatic mode (E mode) to electromagnetic mode (H mode) and from H mode to E mode occur. In previous studies, only a few works paid attention to the effects of the impedance matching network. Cunge et al. [Plasma Sources Sci. Technol. 8, 576 (1999)] investigated the E-H and H-E mode transitions under two different impedance matching situations, but no physical mechanism or interpretation was presented. This issue is remained to be systematically and quantitatively investigated, and the underlying mechanism to be unveiled. In this paper, the effects of the impedance matching network were experimentally studied in electropositive argon gas by varying the series capacitance in an inversely L-shaped matching network. The positive and negative feedback regions are established according to the effect of varying the series capacitance on the output power of the rf power supply. It was found that under the same experimental parameters, the discharge mode transitions are apt to be discontinuous and continuous in the positive and negative feedback regions, respectively. In addition, the critical coil rf current (or applied power) at the mode transition, the hysteretic loop width, and the difference in applied power during the discharge mode transition vary with the series capacitance. The critical coil rf current at the E-H mode transition is not always higher than that at the H-E mode transition.

  10. Unbiased estimation in seamless phase II/III trials with unequal treatment effect variances and hypothesis-driven selection rules.

    PubMed

    Robertson, David S; Prevost, A Toby; Bowden, Jack

    2016-09-30

    Seamless phase II/III clinical trials offer an efficient way to select an experimental treatment and perform confirmatory analysis within a single trial. However, combining the data from both stages in the final analysis can induce bias into the estimates of treatment effects. Methods for bias adjustment developed thus far have made restrictive assumptions about the design and selection rules followed. In order to address these shortcomings, we apply recent methodological advances to derive the uniformly minimum variance conditionally unbiased estimator for two-stage seamless phase II/III trials. Our framework allows for the precision of the treatment arm estimates to take arbitrary values, can be utilised for all treatments that are taken forward to phase III and is applicable when the decision to select or drop treatment arms is driven by a multiplicity-adjusted hypothesis testing procedure. © 2016 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd. PMID:27103068

  11. Unbiased estimation in seamless phase II/III trials with unequal treatment effect variances and hypothesis-driven selection rules.

    PubMed

    Robertson, David S; Prevost, A Toby; Bowden, Jack

    2016-09-30

    Seamless phase II/III clinical trials offer an efficient way to select an experimental treatment and perform confirmatory analysis within a single trial. However, combining the data from both stages in the final analysis can induce bias into the estimates of treatment effects. Methods for bias adjustment developed thus far have made restrictive assumptions about the design and selection rules followed. In order to address these shortcomings, we apply recent methodological advances to derive the uniformly minimum variance conditionally unbiased estimator for two-stage seamless phase II/III trials. Our framework allows for the precision of the treatment arm estimates to take arbitrary values, can be utilised for all treatments that are taken forward to phase III and is applicable when the decision to select or drop treatment arms is driven by a multiplicity-adjusted hypothesis testing procedure. © 2016 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

  12. Effects Of Three-Dimensional Conducting Structures On Resistive Wall Modes

    SciTech Connect

    Villone, Fabio

    2008-11-01

    This paper illustrates the effect of three-dimensional conducting structures on the evolution of Resistive Wall Modes (RWM) occurring in toroidal fusion devices. The CarMa code is used to derive the model, which then is used to design a feedback controller of RWMs. Some examples of application to the ITER geometry are reported.

  13. Effects of Presentation Mode and Computer Familiarity on Summarization of Extended Texts

    ERIC Educational Resources Information Center

    Yu, Guoxing

    2010-01-01

    Comparability studies on computer- and paper-based reading tests have focused on short texts and selected-response items via almost exclusively statistical modeling of test performance. The psychological effects of presentation mode and computer familiarity on individual students are under-researched. In this study, 157 students read extended…

  14. The Relative Effects of Explicit Correction and Recasts on Two Target Structures via Two Communication Modes

    ERIC Educational Resources Information Center

    Yilmaz, Yucel

    2012-01-01

    This study investigated the effects of negative feedback type (i.e., explicit correction vs. recasts), communication mode (i.e., face-to-face communication vs. synchronous computer-mediated communication), and target structure salience (i.e., salient vs. nonsalient) on the acquisition of two Turkish morphemes. Forty-eight native speakers of…

  15. An Analysis of Mode Effects in the 2010 Course Experience Questionnaire

    ERIC Educational Resources Information Center

    Carroll, David

    2011-01-01

    Historically, responses to the Course Experience Questionnaire (CEQ) were required to be collected by self-administered paper or online questionnaire to be eligible for official analysis. CEQ responses collected by telephone were excluded from the final analysis file to minimise the potential for bias due to mode effects: systematic variation in…

  16. Comparative Effects of Two Modes of Computer-Assisted Instructional Package on Solid Geometry Achievement

    ERIC Educational Resources Information Center

    Gambari, Isiaka Amosa; Ezenwa, Victoria Ifeoma; Anyanwu, Romanus Chogozie

    2014-01-01

    The study examined the effects of two modes of computer-assisted instructional package on solid geometry achievement amongst senior secondary school students in Minna, Niger State, Nigeria. Also, the influence of gender on the performance of students exposed to CAI(AT) and CAI(AN) packages were examined. This study adopted a pretest-posttest…

  17. The Effects of Frequency, Distribution, Mode of Presentation, and First Language on Learning an Artificial Language

    ERIC Educational Resources Information Center

    Miyata, Munehiko

    2011-01-01

    This dissertation presents results from a series of experiments investigating adult learning of an artificial language and the effects that input frequency (high vs. low token frequency), frequency distribution (skewed vs. balanced), presentation mode (structured vs. scrambled), and first language (English vs. Japanese) have on such learning.…

  18. The Effects of Communication Mode on Negotiation of Meaning and Its Noticing

    ERIC Educational Resources Information Center

    Yuksel, Dogan; Inan, Banu

    2014-01-01

    This study examined the effects of communication mode ("i.e.", face to face versus computer mediated communication) on the instances of negotiation of meaning (NofM) and its level of noticing by learners. Sixty-four participants (32 dyads) completed two jigsaw tasks in two different mediums (one in each) and four days after the tasks…

  19. Effect of sodium hexanitrocobaltate (III) decomposition on its staining of intracellular potassium ions.

    PubMed

    Green, D B; Dodge, S M; Lee, J R; Tallman, G

    1990-01-01

    The effect was examined of the chemical decomposition of the potassium stain sodium hexanitrocobaltate (III) (SHC), on its ability to produce stain granules of consistent size that could be used to estimate the K+ contents of stomatal guard cells. Stomata in detached epidermis from leaves of Vicia faba (fava bean) were stimulated to accumulate K+ by treating them with fusicoccin. Stomatal apertures and the fraction of guard cell area covered by K+ precipitate granules (K+ score) were measured by digitizing photographic enlargements, and K+ scores were correlated with the age of stain that had been stored either in open or closed containers. The ability of stain aged in open containers to produce consistent fractional cell coverage was compared to 1) the ability of identically treated stain to precipitate K+ from solutions of KCI, and to 2) the kinetics of decomposition of SHC. It was found that the fractional coverage of guard cells of stomata opened to the same apertures decreased with a first order rate constant of 2.3 x 10(-5)/sec. The mass of precipitate formed by treatment of KCl solutions was unchanged for 2 hr after initial preparation of the SHC, and decreased thereafter with a first order rate constant of 1.0 x 10(-5)/sec. When stored in tightly sealed containers, nearly 100 hr were required for an occasionally opened bottle of SHC to decay to the same efficacy as a solution left open to the air for 8 hr. PMID:1694311

  20. Effects of underwater turbulence on laser beam propagation and coupling into single-mode optical fiber.

    PubMed

    Hanson, Frank; Lasher, Mark

    2010-06-01

    We characterize and compare the effects of turbulence on underwater laser propagation with theory. Measurements of the coupling efficiency of the focused beam into a single-mode fiber are reported. A simple tip-tilt control system, based on the position of the image centroid in the focal plane, was shown to maintain good coupling efficiency for a beam radius equal to the transverse coherence length, r(0). These results are relevant to high bandwidth communication technology that requires good spatial mode quality.

  1. Model-OA wind turbine generator - Failure modes and effects analysis

    NASA Technical Reports Server (NTRS)

    Klein, William E.; Lali, Vincent R.

    1990-01-01

    The results failure modes and effects analysis (FMEA) conducted for wind-turbine generators are presented. The FMEA was performed for the functional modes of each system, subsystem, or component. The single-point failures were eliminated for most of the systems. The blade system was the only exception. The qualitative probability of a blade separating was estimated at level D-remote. Many changes were made to the hardware as a result of this analysis. The most significant change was the addition of the safety system. Operational experience and need to improve machine availability have resulted in subsequent changes to the various systems, which are also reflected in this FMEA.

  2. Effects of sediment characteristics on the toxicity of chromium(III) and chromium(VI) to the amphipod, Hyalella azteca

    USGS Publications Warehouse

    Besser, J.M.; Brumbaugh, W.G.; Kemble, N.E.; May, T.W.; Ingersoll, C.G.

    2004-01-01

    We evaluated the influence of sediment characteristics, acid-volatile sulfide (AVS) and organic matter (OM), on the toxicity of chromium (Cr) in freshwater sediments. We conducted chronic (28-42-d) toxicity tests with the amphipod Hyalella azteca exposed to Cr(VI) and Cr(III) in water and in spiked sediments. Waterborne Cr(VI) caused reduced survival of amphipods with a median lethal concentration (LC50) of 40 ??g/L. Cr(VI) spiked into test sediments with differing levels of AVS resulted in graded decreases in AVS and sediment OM. Only Cr(VI)-spiked sediments with low AVS concentrations (<1 ??mol/g) caused significant amphipod mortality. Waterborne Cr(III) concentrations near solubility limits caused decreased survival of amphipods at pH 7 and pH 8 but not at pH 6. Sediments spiked with high levels of Cr(III) did not affect amphipod survival but had minor effects on growth and inconsistent effects on reproduction. Pore waters of some Cr(III)-spiked sediments contained measurable concentrations of Cr(VI), but observed toxic effects did not correspond closely to Cr concentrations in sediment or pore waters. Our results indicate that risks of Cr toxicity are low in freshwater sediments containing substantial concentrations of AVS.

  3. Effects of mitochondrial complex III disruption in the respiratory chain of Neurospora crassa.

    PubMed

    Duarte, Margarida; Videira, Arnaldo

    2009-04-01

    In mitochondria from most organisms, including Neurospora crassa, dimeric complex III was found associated with complex I. Additional association of complex IV with this core structure leads to the formation of a respirasome. It was recently described for bacteria and mammals that complex III is needed for the assembly/stability of complex I. To elucidate the role of complex III in the organization of the respiratory chain of N. crassa, we analysed strains devoid of either the Rieske iron-sulphur or the COREII polypeptide subunits. The mutants display reduced growth, are female sterile and lack active complex III. The supramolecular organization of the oxidative phosphorylation system was characterized by electrophoretic analyses and the efficiency of the respiratory chain analysed by oxygen consumption measurements. The results obtained indicate that absence of complex III activity is not associated with the absence of complex I or complex IV, and leads to the induction of alternative oxidase. Complex III mutant mitochondria are devoid of respirasomes but contain significant amounts of dimeric complex I (I(2)) and of the supercomplex I(1)IV(1). Moreso, for the first time the alternative oxidase was found associated with dimeric complex IV and with supercomplex I(1)IV(1).

  4. Design of controlled rocking steel frames to limit higher mode effects

    NASA Astrophysics Data System (ADS)

    Andree Wiebe, Lydell Deighton

    Because conventional seismic force resisting systems rely on yielding of key structural members to limit seismic forces, structural damage is expected after a design-level earthquake. Repairing this damage can be very expensive, if it is possible at all. Researchers have been developing a new family of self-centring systems that avoid structural damage. One such system is a controlled rocking steel frame, which is the subject of this thesis. In a controlled rocking steel frame, the columns of a frame are permitted to uplift from the foundation, and the response is controlled by using a combination of post-tensioning and energy dissipation. Although previous studies have confirmed the viability of this system, they have also shown that rocking does not fully limit the peak seismic forces because of higher mode effects. If a structure is designed to account for these effects, it may be uneconomical, but if it is not designed to account for them, it may be unsafe. The purpose of this thesis is to develop recommendations for the design of controlled rocking steel frames, particularly with regard to higher mode effects. A theoretical framework for understanding higher mode effects is developed, and large-scale shake table testing is used to study the behaviour of a controlled rocking steel frame. Two mechanisms are proposed to mitigate the increase in structural forces due to higher mode effects, and these mechanisms are validated by shake table testing. Numerical modelling of controlled rocking steel frames is shown to become more reliable when higher mode mitigation mechanisms are used to limit the seismic response. In the final chapters, the thesis proposes and validates a new methodology for the limit states design of controlled rocking steel frames.

  5. [Effects of different planting modes on the soil permeability of sloping farmlands in purple soil area].

    PubMed

    Li, Jian-Xing; He, Bing-Hui; Mei, Xue-Mei; Liang, Yan-Ling; Xiong, Jian

    2013-03-01

    Taking bare land as the control, this paper studied the effects of different planting modes on the soil permeability of sloping farmlands in purple soil area. For the test six planting modes, the soil permeability was in the order of Eriobotrya japonica > Citrus limon > Vetiveria zizanioides hedgerows +corn >Leucaena leucocephala hedgerows + corn> Hemerocallis fulva > corn> bare land, and decreased with increasing depth. The eigenvalues of soil infiltration were in the order of initial infiltration rate> average infiltration rate> stable infiltration rate. The soil permeability had significant positive linear correlations with soil total porosity, non-capillary porosity, initial moisture content, water holding capacity, and organic matter content, and significant negative linear correlation with soil bulk density. The common empirical infiltration model could well fit the soil moisture infiltration processes under the six planting modes, while the Kostiakov equation could not. PMID:23755487

  6. Effect of manganese and nitrogen on the solidification mode in austenitic stainless steel welds

    NASA Astrophysics Data System (ADS)

    Suutala, N.

    1982-12-01

    The macrostructures and microstructures of thirty different austenitic stainless welds alloyed with manganese and Jor nitrogen are analyzed. Comparison of the results with those obtained from normal welds of the AISIJAWS 300 series indicates that the solidification mode and Ferrite Number can be predicted adequately using chromium and nickel equivalents. The solidification mode in the normal and nitrogen-alloyed welds can be best described by the equivalents developed by Hammar and Svensson and the Ferrite Number by the conventional Schaeffler-DeLong diagram. Both of these descriptions are invalid at high manganese content values (5 to 8 pct), however, in which case Hull’s equivalents give a better correlation between the composition and the solidification mode or Ferrite Number. The complicated role of manganese and the austenite-favoring effect of nitrogen in austenitic stainless steels are discussed.

  7. [Effects of different planting modes on the soil permeability of sloping farmlands in purple soil area].

    PubMed

    Li, Jian-Xing; He, Bing-Hui; Mei, Xue-Mei; Liang, Yan-Ling; Xiong, Jian

    2013-03-01

    Taking bare land as the control, this paper studied the effects of different planting modes on the soil permeability of sloping farmlands in purple soil area. For the test six planting modes, the soil permeability was in the order of Eriobotrya japonica > Citrus limon > Vetiveria zizanioides hedgerows +corn >Leucaena leucocephala hedgerows + corn> Hemerocallis fulva > corn> bare land, and decreased with increasing depth. The eigenvalues of soil infiltration were in the order of initial infiltration rate> average infiltration rate> stable infiltration rate. The soil permeability had significant positive linear correlations with soil total porosity, non-capillary porosity, initial moisture content, water holding capacity, and organic matter content, and significant negative linear correlation with soil bulk density. The common empirical infiltration model could well fit the soil moisture infiltration processes under the six planting modes, while the Kostiakov equation could not.

  8. Jamming effects on code synchronization of burst-mode frequency-hop spread-spectrum

    NASA Astrophysics Data System (ADS)

    van Grouw, Mike G.; Wicker, Mark A.

    The authors characterize the performance of a multiple-dwell FHSS (frequency-hopping spread-spectrum) code synchronization scheme in the presence of channel dynamics. Random hop jamming is assumed. The coarse acquisition system uses both passive and active correlation to implement a serial search of the code-uncertainty region. The in-lock monitoring is accomplished using a two-dwell active correlator with a relatively long integration time. Both burst- and continuous-mode communications links are considered. Appropriate performance parameters are developed, and design considerations are discussed. Performance curves are given for the various cases considered. Although a fixed-threshold multiple-dwell synchronization scheme adequately mitigates the effects of dynamic jamming in a continuous-mode communications link, it is shown to be inadequate for a burst-mode communications link.

  9. Communication: Effects of thermionic-gun parameters on operating modes in ultrafast electron microscopy

    PubMed Central

    Kieft, Erik; Schliep, Karl B.; Suri, Pranav K.; Flannigan, David J.

    2015-01-01

    Ultrafast electron microscopes with thermionic guns and LaB6 sources can be operated in both the nanosecond, single-shot and femtosecond, single-electron modes. This has been demonstrated with conventional Wehnelt electrodes and absent any applied bias. Here, by conducting simulations using the General Particle Tracer code, we define the electron-gun parameter space within which various modes may be optimized. The properties of interest include electron collection efficiency, temporal and energy spreads, and effects of laser-pulse duration incident on the LaB6 source. We find that collection efficiencies can reach 100% for all modes, despite there being no bias applied to the electrode. PMID:26798820

  10. TESTING MASS LOSS IN LARGE MAGELLANIC CLOUD CEPHEIDS USING INFRARED AND OPTICAL OBSERVATIONS. II. PREDICTIONS AND TESTS OF THE OGLE-III FUNDAMENTAL-MODE CEPHEIDS

    SciTech Connect

    Neilson, Hilding R.; Ngeow, Chow-Choong; Kanbur, Shashi M.; Lester, John B.

    2010-06-20

    In this paper, we test the hypothesis that Cepheids have infrared excesses due to mass loss. We fit a model using the mass-loss rate and the stellar radius as free parameters to optical observations from the OGLE-III survey and infrared observations from the Two Micron All Sky Survey and SAGE data sets. The sample of Cepheids has predicted minimum mass-loss rates ranging from 0 to 10{sup -8} M{sub sun} yr{sup -1}, where the rates depend on the chosen dust properties. We use the predicted radii to compute the period-radius relation for LMC Cepheids and to estimate the uncertainty caused by the presence of infrared excess for determining angular diameters with the infrared surface brightness technique. Finally, we calculate the linear and nonlinear period-luminosity (P-L) relations for the LMC Cepheids at VIJHK + IRAC wavelengths and find that the P-L relations are consistent with being nonlinear at infrared wavelengths contrary to previous results.

  11. Effects of line-tied boundary conditions on internal current-driven kink mode

    NASA Astrophysics Data System (ADS)

    Mirnov, V. V.; Forest, C. B.; Hegna, C. C.

    2006-04-01

    MHD kink instabilities caused by current passing though high temperature plasma in magnetic field is a topic of importance to astrophysical and lab plasmas. Recent theoretical study of external kink mode stability in line-tied geometry[1] has shown the existence of complex axial wave numbers kz in spatial spectrum of the system. Similar to the external kink mode complex kz were found in numerical calculations performed at LANL for line-tied internal kink instability. We are developing an analytical model for internal mode in line-tied cylindrical geometry to follow transition from the case of periodic cylinder where all axial wave numbers are real to line-tied boundary conditions (BC). The model allows us to determine whether line-tying BC change axial modes globally or their effect is ``shielded'' in long systems in the vicinity of the end-plates. This is important for mode structure and, specifically, for perturbed current profile (``current sheet'') which is localized on the resonance surface in periodic case and is broadened due to superposition of ``quasi-resonances'' in line-tied geometry. [1] V.V.Mirnov et al., Bull. of the APS, v.50, No 8, p.238, DPP Meeting, Oct. 24-28, 2005

  12. An improved method for risk evaluation in failure modes and effects analysis of CNC lathe

    NASA Astrophysics Data System (ADS)

    Rachieru, N.; Belu, N.; Anghel, D. C.

    2015-11-01

    Failure mode and effects analysis (FMEA) is one of the most popular reliability analysis tools for identifying, assessing and eliminating potential failure modes in a wide range of industries. In general, failure modes in FMEA are evaluated and ranked through the risk priority number (RPN), which is obtained by the multiplication of crisp values of the risk factors, such as the occurrence (O), severity (S), and detection (D) of each failure mode. However, the crisp RPN method has been criticized to have several deficiencies. In this paper, linguistic variables, expressed in Gaussian, trapezoidal or triangular fuzzy numbers, are used to assess the ratings and weights for the risk factors S, O and D. A new risk assessment system based on the fuzzy set theory and fuzzy rule base theory is to be applied to assess and rank risks associated to failure modes that could appear in the functioning of Turn 55 Lathe CNC. Two case studies have been shown to demonstrate the methodology thus developed. It is illustrated a parallel between the results obtained by the traditional method and fuzzy logic for determining the RPNs. The results show that the proposed approach can reduce duplicated RPN numbers and get a more accurate, reasonable risk assessment. As a result, the stability of product and process can be assured.

  13. Non-Markovian reduced dynamics based upon a hierarchical effective-mode representation

    SciTech Connect

    Burghardt, Irene; Martinazzo, Rocco; Hughes, Keith H.

    2012-10-14

    A reduced dynamics representation is introduced which is tailored to a hierarchical, Mori-chain type representation of a bath of harmonic oscillators which are linearly coupled to a subsystem. We consider a spin-boson system where a single effective mode is constructed so as to absorb all system-environment interactions, while the residual bath modes are coupled bilinearly to the primary mode and among each other. Using a cumulant expansion of the memory kernel, correlation functions for the primary mode are obtained, which can be suitably approximated by truncated chains representing the primary-residual mode interactions. A series of reduced-dimensional bath correlation functions is thus obtained, which can be expressed as Fourier-Laplace transforms of spectral densities that are given in truncated continued-fraction form. For a master equation which is second order in the system-bath coupling, the memory kernel is re-expressed in terms of local-in-time equations involving auxiliary densities and auxiliary operators.

  14. Saharan dust coarse mode effective radius retrieved from IASI over the Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Peyridieu, S.; Capelle, V.; Tsamalis, C.; Pierangelo, C.; Chédin, A.

    2012-04-01

    Infrared Atmospheric Sounder Interferometer (IASI) observations have been interpreted in terms of monthly mean, 1°x1°, 10 μm dust layer aerosol optical depth (DOD), mean altitude and coarse mode effective radius. The geographical area of the present study concerns the northern tropical Atlantic, a region regularly affected by strong dust events. The method developed relies on the construction of Look-Up-Tables computed for a large selection of atmospheric situations and observing conditions and follows three main steps: determination of the observed atmospheric thermodynamic situation, determination of the dust layer mean optical depth and altitude, and determination of the mean coarse mode effective radius, Reff. This presentation focuses on the latter variable. The main advantage of using infrared radiances is the fact that infrared radiation is mainly sensitive to coarse mode particles, the effect of the accumulation mode and of the width of the distribution being negligible, once the DOD is given. Therefore, the only remaining parameter to be retrieved is Reff. "Radius-Look-Up Tables", sampling different values of the dust infrared optical depth, mean altitude and Reff, using a monomodal lognormal size distribution, are built for four IASI channels close to 9.32 µm. They are selected for their high sensitivity to dust size and insensitivity to other atmospheric components or to dust asphericity. From an analysis of the performances of this algorithm made by Pierangelo et al. (2005) it results that the coarse mode effective radius is retrieved with an accuracy varying from 0.5 µm for smaller radii to 1 µm for larger radii. The monthly mean, 1°x1°, dust coarse mode effective radius is retrieved from IASI over the Atlantic Ocean for the period July 2007 to December 2011. Results compare well with measurements from aircraft and ground based campaigns, or sun-photometer observations (AERONET). During the dust season (summer), we find that Reff remains almost

  15. IS THE BLAZHKO EFFECT THE BEATING OF A NEAR-RESONANT DOUBLE-MODE PULSATION?

    SciTech Connect

    Bryant, Paul H.

    2015-03-20

    In this paper it is shown that the Blazhko effect may result from a near-resonant type of multi-mode pulsation, where two (or sometimes more) periodic oscillations with slightly different frequencies gradually slip in phase, producing a beat frequency type of modulation. Typically one of these oscillations is strongly non-sinusoidal. Two oscillations are sufficient for the standard Blazhko effect; additional oscillations are needed to explain multi-frequency modulation. Previous work on this hypothesis by Arthur N. Cox and others is extended in this paper by developing a simple (non-hydrocode) model that can accurately reproduce several important features found in Kepler data for RR Lyr, including the pulsation waveform; the upper and lower Blazhko envelope functions; and the motion, disappearance, and reappearance of the bump feature. The non-sinusoidal oscillation is probably generated by the fundamental mode and the other oscillations are probably generated by nonradial modes. This model provides an explanation for the strong asymmetry observed in the side peak spectra of most RR Lyrae stars. The motion and disappearance of the bump feature are shown to be illusions, just artifacts of combining the oscillations. V445 Lyr is presented as an example with dual modulation. The mysterious double-maxima waveform observed for this star is explained, providing additional strong evidence that this beating-modes hypothesis is correct. Problems with other recent explanations of the Blazhko effect are discussed in some detail.

  16. Enhancement in Magnetoelectric Effects at Thickness Modes of Layered Ferromagnets and Ferroelectrics

    NASA Astrophysics Data System (ADS)

    Filippov, D. A.; Bichurin, M. I.; Petrov, V. M.; Laletsin, V. M.; Srinivasan, G.; Nan, C. W.

    2006-03-01

    Magnetoelectric (ME) effects in magnetic - piezoelectric heterostructures are caused by mechanical coupling between magnetic and piezoelectric layers. We reported earlier on the theory and observation of a resonant enhancement in the ME effects when the electrical subsystem is driven to resonance, i.e., electromechanical resonance (EMR) associated with radial acoustic modes [1]. Here we discuss the theory and data for ME effects associated with thickness EMR modes. Profiles of ME voltage coefficients versus frequency were estimated for trilayers based lead zirconate titanate and the following ferromagnetic phases: cobalt ferrite, nickel ferrite and lithium ferrite and Fe, Co and Ni. The results are compared with data on samples 10 mm in diameter and 2 mm in thickness. An enhacement in the ME voltage due to radial modes is observed at 350 kHz. A similar behavior due to the thickness mode is observed at 1.5-2 MHz, in agreement with the theory. Calculated ME voltage coefficients versus frequency profiles are in excellent agreement with data. - supported by an NSF grant. [1] D. A. Filippov, M. I. Bichurin, V. M. Petrov, V. M. Laletin, G. Srinivasan, Phys. Solid State 46, 1674, (2004).

  17. Investigation of the effect of resistive MHD modes on spherical torus performance in CDX-U

    SciTech Connect

    Ono, M.; Stutman, D.; Hwang, Y.S.

    1997-01-01

    Resistive MHD modes and associated effects on spherical torus performance are investigated in the CDX-U device for Ip {le} 100 kA. Presently, the growth of resistive MHD modes (n=1/m=3 or n=1/m=2) as the edge q[q(a)] is lowered toward 3.5 appears to limit the maximum current achievable in CDX-U. For low q(a) discharges, a prominent rotating hot spot can be seen with the soft x-ray array, indicative of a magnetic island associated with a n=1/m=1 mode. The edge mode, which is n=1/m=3 or n=1/m=2, can be seen by the soft x-ray and edge magnetic pick up coil array. The growth of those modes in space and amplitude eventually leads to an Internal Reconnection Event (IRE). Prior to the IRE, strong mode-mixing takes place suggesting magnetic island overlap. The IRE causes a rapid heat loss from the core causing a strong plasma elongation and current spike due to the plasma inductance drop. With an appropriate discharge control, a MHD quiescent high confinement regime with over twice the central electron temperature relative to the MHD active regime has been found. To assess the halo-induced effects during the MHD events, a pair of segmented Rogowski coils were installed on the center stack. The observed halo-induced current fraction is generally small (less than 5% of the total plasma current) even for the case of forced disruption.

  18. Theory of magnetoelectric effect in multilayer nanocomposites on a substrate: Resonant bending-mode response

    NASA Astrophysics Data System (ADS)

    Krantz, Matthias C.; Gerken, Martina

    2013-05-01

    Resonant bending-mode magnetoelectric (ME) coefficients of magnetostrictive-piezoelectric multilayer cantilevers are calculated analytically using a model developed for arbitrary multilayers on a substrate. Without quality factor effects the ME coefficient maxima in the four-dimensional parameter space of layer numbers, layer sequences, piezoelectric volume fractions, and substrate thicknesses are found to be essentially constant for nonzero substrate thickness. Global maxima occur for bilayers without substrates. Vanishing magnetoelectric response regions result from voltage cancellation in piezoelectric layers or absence of bending-mode excitation. They are determined by the neutral plane position in the multilayer stack. With Q-factor effects dominated by viscous air damping ME coefficients strongly increase with cantilever thickness primarily due to increasing resonance frequencies. The results yield a layer specific prediction of ME coefficients, resonance frequencies, and Q-factors in arbitrary multilayers and thus distinction of linear-coupling and Q-factor effects from exchange interaction, interface, or nonlinear ME effects.

  19. Forecasting Device Effectiveness: Volume III. Analytic Assessment of Device Effectiveness Forecasting Technique. Final Report.

    ERIC Educational Resources Information Center

    Rose, Andrew M.; And Others

    This third of three volumes reports on analytic procedures conducted to address various aspects of the scalar properties of the Device Effectiveness Forecasting Technique (DEFT). DEFT, a series of microcomputer programs applied to data gathered from rating scales, is used to evaluate simulator devices used in U.S. Army weapons training. The…

  20. Effect of nucleosides and a nucleotide mixture on proliferation of human gastric cancer cells (KATO III).

    PubMed

    Wang, J; Usami, M; Yasuda, I; Kasahara, H; Kotani, G; Cao, Y; Zheng, J; Iso, A; Kanamaru, T; Ohyanagi, H

    1994-04-01

    The effect of the nucleotides and a nucleotide mixture (OG-VI), consisting of inosine, guanosine 5'-monophosphate (5'-GMP), cytidine, uridine, thymidine (TdR) (4:4:4:3:1 in molar ratio), and TdR co-administration on proliferation of KATO III human gastric cancer cells in culture was evaluated. Consumption of purine and pyrimidine by cancer cells and changes in cell number with OG-VI or TdR were compared with the control culture medium (Williams E) after 72 hour-culture. Addition of OG-VI or TdR did not enhance the cellular proliferation, but inhibited growth when given in higher concentrations (0.3-3 mM inosine, 0.3-3 mM 5'-GMP, 0.22-2.2 mM uridine, 74-740 microM TdR). Consumption rate of TdR in the medium was less in the TdR group, 33.7%, than in the OG-VI group, 72.2% (p < 0.05). This suggests that TdR metabolism is modulated by other nucleosides and nucleotide included in OG-VI. Under the coadministration of 5-fluorouracil (FUra), addition of OG-VI or TdR suppressed cellular proliferation (p < 0.05). The inhibition rate of cellular proliferation in the OG-VI group was slightly higher than the TdR group, but there was no statistically significant difference between the two groups. The combination of FUra with OG-VI or TdR enhances the antitumor effect of FUra. It is concluded that the OG-VI does not enhance the tumor cell proliferation and it is a potential biochemical modulator of FUra metabolism in human cancer cells. PMID:7823535

  1. Band structure effects on resonant tunneling in III-V quantum wells versus two-dimensional vertical heterostructures

    NASA Astrophysics Data System (ADS)

    Campbell, Philip M.; Tarasov, Alexey; Joiner, Corey A.; Ready, W. Jud; Vogel, Eric M.

    2016-01-01

    Since the invention of the Esaki diode, resonant tunneling devices have been of interest for applications including multi-valued logic and communication systems. These devices are characterized by the presence of negative differential resistance in the current-voltage characteristic, resulting from lateral momentum conservation during the tunneling process. While a large amount of research has focused on III-V material systems, such as the GaAs/AlGaAs system, for resonant tunneling devices, poor device performance and device-to-device variability have limited widespread adoption. Recently, the symmetric field-effect transistor (symFET) was proposed as a resonant tunneling device incorporating symmetric 2-D materials, such as transition metal dichalcogenides (TMDs), separated by an interlayer barrier, such as hexagonal boron-nitride. The achievable peak-to-valley ratio for TMD symFETs has been predicted to be higher than has been observed for III-V resonant tunneling devices. This work examines the effect that band structure differences between III-V devices and TMDs has on device performance. It is shown that tunneling between the quantized subbands in III-V devices increases the valley current and decreases device performance, while the interlayer barrier height has a negligible impact on performance for barrier heights greater than approximately 0.5 eV.

  2. Photodegradation of parabens by Fe(III)-citrate complexes at circumneutral pH: matrix effect and reaction mechanism.

    PubMed

    Feng, Xiaonan; Chen, Yong; Fang, Yuan; Wang, Xiaoyue; Wang, Zongping; Tao, Tao; Zuo, Yuegang

    2014-02-15

    The photodegradation of four parabens including methyl-, ethyl-, propyl-, and butyl-paraben in the presence of Fe(III)-citrate complexes under simulated sunlight was investigated. The degradation of parabens increased with decreasing pH within the range of 5.0-8.0 at the Fe(III)-to-citrate ratio of 10:150 (μM). The addition of low-molecular-weight carboxylic acids showed different effects on the photodegradation of methylparaben. The low-photoreactive carboxylic acids inhibited the photodegradation of methylparaben in the order of formic acid>succinic acid>acetic acid>malonic acid. In contrast, oxalic acid enhanced the photodegradation and exhibited appreciable synergistic effect with Fe(III)-citrate at concentration higher than 500 μM. Up to 99.0% of substrate was degraded after 30 min at pH6.0 in the Fe(III)-citrate-oxalate system. The various fractions of fulvic acid inhibited the photodegradation of methylparaben. The inhibition increased with increasing nominal molecular weight of fractionated fulvic acid. Moreover, the photodegradation of methylparaben was inhibited in natural waters in the order of Liangzi Lake

  3. Field and dilution effects on the magnetic relaxation behaviours of a 1D dysprosium(iii)-carboxylate chain built from chiral ligands.

    PubMed

    Han, Tian; Leng, Ji-Dong; Ding, You-Song; Wang, Yanyan; Zheng, Zhiping; Zheng, Yan-Zhen

    2015-08-14

    A one-dimensional dysprosium(iii)-carboxylate chain in which the Dy(III) ions sit in a pseudo D(2d)-symmetry environment is synthesized and shows different slow magnetic relaxation behaviours depending on the field and dilution effects. Besides, the chiral ligand introduces the additional functions of the Cotton effect and polarization for this compound. PMID:26159885

  4. Global Hybrid Simulations of Energetic Particle Effects on the n=1 Mode in Tokamaks: Internal Kink and Fishbone Instability

    SciTech Connect

    G.Y. Fu; W. Park; H.R. Strauss; J. Breslau; J. Chen; S. Jardin; L.E. Sugiyama

    2005-08-09

    Global hybrid simulations of energetic particle effects on the n=1 internal kink mode have been carried out for tokamaks. For the International Thermonuclear Experimental Reactor (ITER) [ITER Physics Basis Editors et al., Nucl. Fusion 39:2137 (1999)], it is shown that alpha particle effects are stabilizing for the internal kink mode. However, the elongation of ITER reduces the stabilization effects significantly. Nonlinear simulations of the precessional drift fishbone instability for circular tokamak plasmas show that the mode saturates due to flattening of the particle distribution function near the resonance region. The mode frequency chirps down rapidly as the flattening region expands radially outward. Fluid nonlinearity reduces the saturation level.

  5. An Investigation of Effective Discharge for Suspended Sediment by Level III Ecoregion

    NASA Astrophysics Data System (ADS)

    Heins, A.; Simon, A.

    2002-12-01

    for seven ecoregions: Coast Range (1) Sierra Nevada (5), Snake River Basin (12), Arizona-New Mexico Plateau (22), Flint Hills (28), Central Irregular Plains (40) and the Mississippi Valley Loess Plains (74). Mean daily flow data for a substantial period of record were divided into 33 logarithmic classes and the percentage occurrence of each of these was computed. The total annual suspended sediment transport was then calculated for each class, using suspended-sediment rating equations generated through regression of instantaneous discharge and suspended sediment concentration historic sample data. The geometric midpoint of the class transporting the greatest annual sediment load was considered to be the effective discharge. Results to date demonstrate in environments as diverse the Sierra Nevada Mountains and the Mississippi Valley Loess Plains, the effective discharge for suspended sediment is close to the 1.5 year flow. In the former ecoregion, the mean recurrence interval of suspended sediment effective discharge was 1.526 years. The eventual aim of this project is to calculate effective discharges for all 2929 USGS gaging stations with sufficient instantaneous suspended sediment and associated discharges measurements. These sites cover all 84 level III ecoregions, permitting environmental and geographic patterns of effective discharge recurrence interval. Calculations will be repeated using higher temporal resolution (15 minute) flow data.

  6. Noncanonical Effects of IRF9 in Intestinal Inflammation: More than Type I and Type III Interferons.

    PubMed

    Rauch, Isabella; Rosebrock, Felix; Hainzl, Eva; Heider, Susanne; Majoros, Andrea; Wienerroither, Sebastian; Strobl, Birgit; Stockinger, Silvia; Kenner, Lukas; Müller, Mathias; Decker, Thomas

    2015-07-01

    The interferon (IFN)-stimulated gene factor 3 (ISGF3) transcription factor with its Stat1, Stat2, and interferon regulatory factor 9 (IRF9) subunits is employed for transcriptional responses downstream of receptors for type I interferons (IFN-I) that include IFN-α and IFN-β and type III interferons (IFN-III), also called IFN-λ. Here, we show in a murine model of dextran sodium sulfate (DSS)-induced colitis that IRF9 deficiency protects animals, whereas the combined loss of IFN-I and IFN-III receptors worsens their condition. We explain the different phenotypes by demonstrating a function of IRF9 in a noncanonical transcriptional complex with Stat1, apart from IFN-I and IFN-III signaling. Together, Stat1 and IRF9 produce a proinflammatory activity that overrides the benefits of the IFN-III response on intestinal epithelial cells. Our results further suggest that the CXCL10 chemokine gene is an important mediator of this proinflammatory activity. We thus establish IFN-λ as a potentially anticolitogenic cytokine and propose an important role for IRF9 as a component of noncanonical Stat complexes in the development of colitis.

  7. Diiron(III)-μ-Fluoro Bisporphyrins: Effect of Bridging Ligand on the Metal Spin State.

    PubMed

    Sil, Debangsu; Kumar, Amit; Rath, Sankar Prasad

    2016-08-01

    A hitherto unknown family of diiron(III)-μ-fluoro bisporphyrins has been synthesized and structurally characterized. Fluoride abstraction from SbF6 (-) and BF4 (-) resulted in the synthesis of the μ-fluoro complexes of ethane- and ethene-bridged diiron(III) bisporphyrins. Two such complexes were structurally characterized, which revealed a single fluoro bridge between two iron centers with a remarkably bent Fe-F-Fe unit. Although isoelectronic with the μ-hydroxo complexes, the μ-fluoro species are quite divergent in terms of the electronic structure and properties. UV/Vis spectroscopy of the μ-fluoro complex exhibits a large redshift (ca. 18 nm) of the Soret band in comparison to their μ-hydroxo analog. Combined analysis by single crystal X-ray structure determination and Mössbauer and (1) H NMR spectroscopy revealed the presence of two equivalent iron(III) centers in the μ-fluoro complexes in both solid and solution phases. In contrast, the iron(III) centers of the μ-hydroxo complexes are known to be inequivalent. Variable-temperature magnetic studies show a weak antiferromagnetic interaction between the iron(III) centers of the μ-fluoro complexes with coupling constants (J) ranging from -33 to -40 cm(-1) . The experimental results were further supported by DFT calculations. PMID:27304611

  8. Noncanonical Effects of IRF9 in Intestinal Inflammation: More than Type I and Type III Interferons

    PubMed Central

    Rauch, Isabella; Rosebrock, Felix; Hainzl, Eva; Heider, Susanne; Majoros, Andrea; Wienerroither, Sebastian; Strobl, Birgit; Stockinger, Silvia; Kenner, Lukas; Müller, Mathias

    2015-01-01

    The interferon (IFN)-stimulated gene factor 3 (ISGF3) transcription factor with its Stat1, Stat2, and interferon regulatory factor 9 (IRF9) subunits is employed for transcriptional responses downstream of receptors for type I interferons (IFN-I) that include IFN-α and IFN-β and type III interferons (IFN-III), also called IFN-λ. Here, we show in a murine model of dextran sodium sulfate (DSS)-induced colitis that IRF9 deficiency protects animals, whereas the combined loss of IFN-I and IFN-III receptors worsens their condition. We explain the different phenotypes by demonstrating a function of IRF9 in a noncanonical transcriptional complex with Stat1, apart from IFN-I and IFN-III signaling. Together, Stat1 and IRF9 produce a proinflammatory activity that overrides the benefits of the IFN-III response on intestinal epithelial cells. Our results further suggest that the CXCL10 chemokine gene is an important mediator of this proinflammatory activity. We thus establish IFN-λ as a potentially anticolitogenic cytokine and propose an important role for IRF9 as a component of noncanonical Stat complexes in the development of colitis. PMID:25918247

  9. The Effect of Intermolecular Modes on the Xh-Stretching Vibrations in Hydrogen Bonded Complexes

    NASA Astrophysics Data System (ADS)

    Mackeprang, Kasper; Kjaergaard, Henrik G.

    2016-06-01

    Vibrational spectra of hydrogen bonded bimolecular complexes (XH\\cdotsY, where X is the hydrogen bond donor atom, and Y is the acceptor atom) have long been a theoretical challenge. Specifically, the XH-stretching motion is difficult to describe due to the effect of the large amplitude intermolecular modes inherent to complexes. We have developed a vibrational model, the Local Mode Perturbation Theory (LMPT) model, to accurately determine the transition wavenumber and oscillator strength of the XH-stretching transition in hydrogen bonded bimolecular complexes. The model is based on a local mode (LM) model of the XH-stretching transition and the effect of the intermolecular modes is included via Rayleigh-Schrödinger perturbation theory. Our model has significantly improved results obtained using the LM model (see Figure). Additionally, our LMPT model does not require a full-dimensional anharmonic calculation, which enables application to large systems and the usage of higher level ab initio theory for the required potential energy surfaces. This work was inspired by our recent efforts to accurately determine equilibrium constants of complex formation, which rely on an accurate determination of the oscillator strength of the XH-stretching transition.

  10. Effects of locally resonant modes on underwater sound absorption in viscoelastic materials.

    PubMed

    Wen, Jihong; Zhao, Honggang; Lv, Linmei; Yuan, Bo; Wang, Gang; Wen, Xisen

    2011-09-01

    Recently, by introducing locally resonant scatterers with spherical shape proposed in phononic crystals into design of underwater sound absorption materials, the low-frequency underwater sound absorption phenomenon induced by the localized resonances is observed. To reveal this absorption mechanism, the effect of the locally resonant mode on underwater sound absorption should be studied. In this paper, the finite element method, which is testified efficiently by comparing the calculation results with those of the layer multiple scattering method, is introduced to investigate the dynamic modes and the corresponding sound absorption of localized resonance. The relationship between the resonance modes described with the displacement contours of one unit cell and the corresponding absorption spectra is discussed in detail, which shows that the localized resonance leads to the absorption peak, and the mode conversion from longitudinal to transverse waves at the second absorption peak is more efficient than that at the first one. Finally, to show the modeling capability of FEM and investigate shape effects of locally resonant scatterers on underwater sound absorption, the absorption properties of viscoelastic materials containing locally resonant scatterers with ellipsoidal shape are discussed.

  11. LETTER: Empirical scaling law for the effective heat diffusivity in ELMy H mode plasmas

    NASA Astrophysics Data System (ADS)

    Becker, G.

    1996-04-01

    Predictive code simulations of high density scenarios of ITER and other reactor-grade devices require an experimentally validated scaling relation for the one-fluid effective heat diffusivity chi in the ELMy H mode regime. A comprehensive empirical chi scaling compatible with the ITERH92-P ELMy H mode scaling of the thermal energy confinement time is presented. It follows from a power law ansatz for chi and integration of the single-fluid energy equation and recovers all the exponents of the global confinement law. The numerical factor of the global scaling is used to calibrate the heat diffusivity. The dependences of chi on the temperature and temperature gradient, connected with the power degradation of confinement, are inferred from profile information of a high density H mode discharge. The scaling law obtained is successfully tested against JET, ASDEX and ASDEX Upgrade H mode discharges covering a wide parameter range. It is found to predict the strong rise of the experimental chi profiles with increasing effective radius

  12. Direct observation of lanthanide(III)-phthalocyanine molecules on Au(111) by using scanning tunneling microscopy and scanning tunneling spectroscopy and thin-film field-effect transistor properties of Tb(III)- and Dy(III)-phthalocyanine molecules.

    PubMed

    Katoh, Keiichi; Yoshida, Yusuke; Yamashita, Masahiro; Miyasaka, Hitoshi; Breedlove, Brian K; Kajiwara, Takashi; Takaishi, Shinya; Ishikawa, Naoto; Isshiki, Hironari; Zhang, Yan Feng; Komeda, Tadahiro; Yamagishi, Masakazu; Takeya, Jun

    2009-07-29

    The crystal structures of double-decker single molecule magnets (SMM) LnPc(2) (Ln = Tb(III) and Dy(III); Pc = phthalocyanine) and non-SMM YPc(2) were determined by using X-ray diffraction analysis. The compounds are isomorphous to each other. The compounds have metal centers (M = Tb(3+), Dy(3+), and Y(3+)) sandwiched by two Pc ligands via eight isoindole-nitrogen atoms in a square-antiprism fashion. The twist angle between the two Pc ligands is 41.4 degrees. Scanning tunneling microscopy was used to investigate the compounds adsorbed on a Au(111) surface, deposited by using the thermal evaporation in ultrahigh vacuum. Both MPc(2) with eight lobes and MPc with four lobes, which has lost one Pc ligand, were observed. In the scanning tunneling spectroscopy images of TbPc molecules at 4.8 K, a Kondo peak with a Kondo temperature (T(K)) of approximately 250 K was observed near the Fermi level (V = 0 V). On the other hand, DyPc, YPc, and MPc(2) exhibited no Kondo peak. To understand the observed Kondo effect, the energy splitting of sublevels in a crystal field should be taken into consideration. As the next step in our studies on the SMM/Kondo effect in Tb-Pc derivatives, we investigated the electronic transport properties of Ln-Pc molecules as the active layer in top- and bottom-contact thin-film organic field effect transistor devices. Tb-Pc molecule devices exhibit p-type semiconducting properties with a hole mobility (mu(H)) of approximately 10(-4) cm(2) V(-1) s(-1). Interestingly, the Dy-Pc based devices exhibited ambipolar semiconducting properties with an electron mobility (mu(e)) of approximately 10(-5) and a mu(H) of approximately 10(-4) cm(2) V(-1) s(-1). This behavior has important implications for the electronic structure of the molecules. PMID:19569681

  13. Noncontact dipole effects on channel permeation. III. Anomalous proton conductance effects in gramicidin

    PubMed Central

    Phillips, LR; Cole, CD; Hendershot, RJ; Cotten, M; Cross, TA; Busath, DD

    1999-01-01

    Proton transport on water wires, of interest for many problems in membrane biology, is analyzed in side-chain analogs of gramicidin A channels. In symmetrical 0.1 N HCl solutions, fluorination of channel Trp(11), Trp-(13), or Trp(15) side chains is found to inhibit proton transport, and replacement of one or more Trps with Phe enhances proton transport, the opposite of the effects on K(+) transport in lecithin bilayers. The current-voltage relations are superlinear, indicating that some membrane field-dependent process is rate limiting. The interfacial dipole effects are usually assumed to affect the rate of cation translocation across the channel. For proton conductance, however, water reorientation after proton translocation is anticipated to be rate limiting. We propose that the findings reported here are most readily interpreted as the result of dipole-dipole interactions between channel waters and polar side chains or lipid headgroups. In particular, if reorientation of the water column begins with the water nearest the channel exit, this hypothesis explains the negative impact of fluorination and the positive impact of headgroup dipole on proton conductance. PMID:20540928

  14. Anharmonic effects in the optical and acoustic bending modes of graphene

    NASA Astrophysics Data System (ADS)

    Ramírez, R.; Chacón, E.; Herrero, C. P.

    2016-06-01

    The out-of-plane fluctuations of carbon atoms in a graphene sheet have been studied by means of classical molecular dynamic simulations with an empirical force field as a function of temperature. The Fourier analysis of the out-of-plane fluctuations often applied to characterize the acoustic bending mode of graphene is extended to the optical branch, whose polarization vector is perpendicular to the graphene layer. This observable is inaccessible in a continuous elastic model of graphene but it is readily obtained by the atomistic treatment. Our results suggest that the long-wavelength limit of the acoustic out-of-plane fluctuations of a free layer without stress is qualitatively similar to that predicted by a harmonic model under a tensile stress. This conclusion is a consequence of the anharmonicity of both in-plane and out-of-plane vibrational modes of the lattice. The most striking anharmonic effect is the presence of a linear term, ωA=vAk , in the dispersion relation of the acoustic bending band of graphene at long wavelengths (k →0 ). This term implies a strong reduction of the amplitude of out-of-plane oscillations in comparison to a flexural mode with a k2 dependence in the long-wavelength limit. Our simulations show an increase of the sound velocity associated to the bending mode, as well as an increase of its bending constant, κ , as the temperature increases. Moreover, the frequency of the optical bending mode, ωO(Γ ), also increases with the temperature. Our results are in agreement with recent analytical studies of the bending modes of graphene using either perturbation theory or an adiabatic approximation in the framework of continuous layer models.

  15. Effects of electron cyclotron current drive on the evolution of double tearing mode

    SciTech Connect

    Sun, Guanglan Dong, Chunying; Duan, Longfang

    2015-09-15

    The effects of electron cyclotron current drive (ECCD) on the double tearing mode (DTM) in slab geometry are investigated by using two-dimensional compressible magnetohydrodynamics equations. It is found that, mainly, the double tearing mode is suppressed by the emergence of the secondary island, due to the deposition of driven current on the X-point of magnetic island at one rational surface, which forms a new non-complete symmetric magnetic topology structure (defined as a non-complete symmetric structure, NSS). The effects of driven current with different parameters (magnitude, initial time of deposition, duration time, and location of deposition) on the evolution of DTM are analyzed elaborately. The optimal magnitude or optimal deposition duration of driven current is the one which makes the duration of NSS the longest, which depends on the mutual effect between ECCD and the background plasma. Moreover, driven current introduced at the early Sweet-Parker phase has the best suppression effect; and the optimal moment also exists, depending on the duration of the NSS. Finally, the effects varied by the driven current disposition location are studied. It is verified that the favorable location of driven current is the X-point which is completely different from the result of single tearing mode.

  16. Effects of Ligand Geometry on the Photophysical Properties of Photoluminescent Eu(III) and Sm(III) 1-Hydroxypyridin-2-one Complexes in Aqueous Solution.

    PubMed

    Daumann, Lena J; Tatum, David S; Andolina, Christopher M; Pacold, Joseph I; D'Aléo, Anthony; Law, Ga-lai; Xu, Jide; Raymond, Kenneth N

    2016-01-01

    A series of 10 tetradentate 1-hydroxy-pyridin-2-one (1,2-HOPO) ligands and corresponding eight-coordinated photoluminescent Eu(III) and Sm(III) complexes were prepared. Generally, the ligands differ by the linear (nLI) aliphatic linker length, from 2 to 8 methylene units between the bidentate 1,2-HOPO chelator units. The photoluminescent quantum yields (Φtot) were found to vary with the linker length, and the same trend was observed for the Eu(III) and Sm(III) complexes. The 2LI and 5LI bridged complexes are the brightest (Φtotxε). The change in ligand wrapping pattern between 2LI and 5LI complexes observed by X-ray diffraction (XRD) is further supported by density functional theory (DFT) calculations. The bimodal Φtot trends of the Eu(III) and Sm(III) complexes are rationalized by the change in ligand wrapping pattern as the bridge (nLI) is increased in length.

  17. Effect of Initial Microtopography and Ultrasonic Treatment Mode on Steel Surface Layer Quality

    NASA Astrophysics Data System (ADS)

    Zaitsev, K. V.; Lychagin, D. V.; Arkhipova, D. A.

    2016-04-01

    The article presents results of studies on the effect of pre-lathed surface micro-relief on surface micro-hardness after ultrasonic plastic treatment, as well as the effect of ultrasonic treatment on structure and properties of surface layers of steels 20 and 40X. The effect of ultrasonic treatment processing modes on roughness and micro-hardness of the surface layers was studied. It is shown that roughness values as well as form of ridges and grooves, obtained by pre-lathing, effect the growth of micro-hardness values after ultrasonic plastic treatment.

  18. Oxidation of Cr(III) on birnessite surfaces: The effect of goethite and kaolinite.

    PubMed

    Zhong, Laiyuan; Yang, Jiewen; Liu, Liming; Xing, Baoshan

    2015-11-01

    Oxidation of Cr(III) by manganese oxides may pose a potential threat to environments due to the formation of toxic Cr(VI) species. At present, it was still unclear whether the extent of Cr(III) oxidation and fate of Cr(VI) would be changed when manganese oxides co-exist with other minerals, the case commonly occurring in soils. This study investigated the influence of goethite and kaolinite on Cr(III) oxidation by birnessite under acidic pH condition (pH3.5) and background electrolyte of 0.01mol/L NaCl. Goethite was found not to affect Cr(III) oxidation, which was interpreted as the result of overwhelming adsorption of cationic Cr(III) onto the negatively-charged birnessite (point of zero charge (PZC)<3.0) rather than the positively-charged goethite (PZC=8.8). However, more Cr(VI) would be retained by the surface with the increase in addition of goethite because of its strong ability on adsorption of Cr(VI) at low pH. Moreover, either Cr(III) oxidation or distribution of the generated Cr(VI) between the solid and solution phases was not affected by kaolinite (PZC<3.0), indicating its low affinity for Cr species. Reactions occurring in the present mixed systems were suggested, which could be partly representative of those in the soils and further indicates that the mobility and risk of Cr(VI) would be decreased if goethite was present.

  19. The effect of holes in the dispersion relation of propagative surface plasmon modes of nanoperforated semitransparent metallic films

    SciTech Connect

    Kekesi, R. Meneses-Rodríguez, D.; García-Pérez, F.; González, M. U.; García-Martín, A.; Cebollada, A.; Armelles, G.

    2014-10-07

    We have analysed the effect that holes have on the properties of propagative surface plasmon modes in semitransparent nanoperforated Au films. The modes have been excited in Kretschmann configuration. Contrary to continuous films, where only one mode is excited, two modes are observed in Au nanohole array. The origin of this different behavior is discussed using effective optical properties for the nanoperforated films. The presence of the holes affects the effective optical constants of the membranes in two ways: it changes the contribution of the free electrons, and it gives rise to a localized transition due to a hole induced plasmon resonance. This localized transition interacts with the propagative surface plasmon modes, originating the two detected modes.

  20. Effect of pH on complex coacervate core micelles from Fe(III)-based coordination polymer.

    PubMed

    Wang, Junyou; de Keizer, Arie; van Leeuwen, Herman P; Yan, Yun; Vergeldt, Frank; van As, Henk; Bomans, Paul H H; Sommerdijk, Nico A J M; Cohen Stuart, Martien A; van der Gucht, Jasper

    2011-12-20

    The effect of pH on iron-containing complex coacervate core micelles [Fe(III)-C3Ms] is investigated in this paper. The Fe(III)-C3Ms are formed by mixing cationic poly(N-methyl-2-vinylpyridinium iodide)-b-poly(ethylene oxide) [P2MVP(41)-b-PEO(205)] and anionic iron coordination polymers [Fe(III)-L(2)EO(4)] at stoichiometric charge ratio. Light scattering and Cryo-TEM have been performed to study the variations of hydrodynamic radius and core structure with changing pH. The hydrodynamic radius of Fe(III)-C3Ms is determined mainly by the corona and does not change very much in a broad pH range. However, Cryo-TEM pictures and magnetic relaxation measurements indicate that the structure of the micellar cores changes upon changing the pH, with a more crystalline, elongated shape and lower relaxivity at high pH. We attribute this to the formation of mixed iron complexes in the core, involving both the bis-ligand and hydroxide ions. These complexes are stabilized toward precipitation by the diblock copolymer.

  1. Correlation of blood Cr(III) and adverse health effects: Application of PBPK modeling to determine non-toxic blood concentrations.

    PubMed

    Monnot, Andrew D; Christian, Whitney V; Paustenbach, Dennis J; Finley, Brent L

    2014-08-01

    Chromium (Cr) (III) is a trace metal essential to human health and exposure typically occurs via the diet on a daily basis. Some groups of individuals, such as those consuming Cr(III) supplements or patients with Cr-containing implants, may have elevated blood Cr(III) concentrations. Although blood Cr(III) levels are thought to be an accurate metric of exposure, little is known about the relationship between these concentrations and possible adverse health risks. This study evaluated the various effects reported in animal and human epidemiological studies of Cr(III) exposure in an attempt to correlate them with blood Cr(III) concentrations. The target endpoints identified in this analysis included the hematological, hepatic, and renal systems. Animal and human physiological-based pharmacokinetic (PBPK) models were used to estimate steady state blood Cr(III) concentrations from a variety of dosing regimens. Based on the animal studies, our results suggest that blood Cr(III) concentrations as high as 480-580 μg/L are not associated with any responses. For each of the three health endpoints considered in this analysis (hematological, hepatic, and renal) no adverse effects were observed below 3,700 μg/L. Some hematological responses were observed at 3,700 μg/L, and adverse effects clearly occurred at 7,500 μg/L. These findings can be used to assess potential health risks to individuals with elevated blood Cr(III) concentrations.

  2. Laser-induced hydrodynamics in water-saturated tissue: III. Optoacoustic effects

    NASA Astrophysics Data System (ADS)

    Yusupov, V. I.; Bulanov, V. V.; Chudnovskii, V. M.; Bagratashvili, V. N.

    2014-01-01

    Studied in this work are specific features of acoustic vibrations generated at the hot blackened tip of an optical fiber (the so-called hot tip) delivering moderate-power (1-10 W) CW laser radiation in contact with water or a water-saturated biotissue. Generated upon such contact is a wideband acoustic signal whose characteristics largely depend on the object exposed and treatment scheme. Placing the hot tip in an acoustic resonator is demonstrated to cause distinct amplitude modulation of the acoustic noise. The formation of laser channels in an intervertebral disc or the intramedullary cavity of a bovine thighbone gives rise to the emission of a quasiperiodic train of pulses associated with the explosive growth and collapse of steam-gas bubbles in the hot-tip-to-biotissue contact region. The resultant pressure pulses, 20 ± 15 MPa in amplitude, cause damage to the adjacent tissue and facilitate the production of a laser channel at a rate of some 0.4-5 mm s-1. During the course of laser treatment the biotissue gradually gets saturated with steam-gas bubbles, which results in the development of low-frequency pressure oscillations in the range 0.1-10 Hz and a gradual pressure rise to around 200 kPa, leading to reduction of the natural frequencies of the resonance modes of the biotissue. The possible effect of these acoustic vibrations on the biotissue is discussed.

  3. Does response mode affect amount recalled or the magnitude of the testing effect?

    PubMed

    Putnam, Adam L; Roediger, Henry L

    2013-01-01

    The testing effect is the finding that retrieval practice can enhance recall on future tests. One unanswered question is whether first-test response mode (writing or speaking the answer) affects final-test performance (and whether final-test response mode itself matters). An additional unsettled issue is whether written and oral recall lead to differences in the amount recalled. In three experiments, we examined these issues: whether subjects can recall more via typing or speaking; whether typing or speaking answers on a first test can lead to better final-test performance (and whether an interaction occurs with final-test response mode) and whether any form of overt response leads to better final-test performance as compared to covert retrieval (thinking of the answer but not producing it). Subjects studied paired associates; took a first test by typing, speaking, or thinking about responses; and then took a second test in which the answers were either spoken or typed. The results revealed few differences between typing and speaking during recall, and no difference in the size of the testing effect on the second test. Furthermore, an initial covert retrieval yielded roughly the same benefit to future test performance as did overt retrieval. Thus, the testing effect was quite robust across these manipulations. The practical implication for learning is that covert retrieval provides as much benefit to later retention as does overt retrieval and that both can be effective study strategies. PMID:22898928

  4. The costs and effectiveness of large Phase III pre-licensure vaccine clinical trials.

    PubMed

    Black, Steven

    2015-01-01

    Prior to the 1980s, most vaccines were licensed based upon safety and effectiveness studies in several hundred individuals. Beginning with the evaluation of Haemophilus influenzae type b conjugate vaccines, much larger pre-licensure trials became common. The pre-licensure trial for Haemophilus influenzae oligosaccharide conjugate vaccine had more than 60,000 children and that of the seven-valent pneumococcal conjugate vaccine included almost 38,000 children. Although trial sizes for both of these studies were driven by the sample size required to demonstrate efficacy, the sample size requirements for safety evaluations of other vaccines have subsequently increased. With the demonstration of an increased risk of intussusception following the Rotashield brand rotavirus vaccine, this trend has continued. However, routinely requiring safety studies of 20,000-50,000 or more participants has two major downsides. First, the cost of performing large safety trials routinely prior to licensure of a vaccine is very large, with some estimates as high at US$200 million euros for one vaccine. This high financial cost engenders an opportunity cost whereby the number of vaccines that a company is willing or able to develop to meet public health needs becomes limited by this financial barrier. The second downside is that in the pre-licensure setting, such studies are very time consuming and delay the availability of a beneficial vaccine substantially. One might argue that in some situations, this financial commitment is warranted such as for evaluations of the risk of intussusception following newer rotavirus vaccines. However, it must be noted that while an increased risk of intussusception was not identified in large pre-licensure studies, in post marketing evaluations an increased risk of this outcome has been identified. Thus, even the extensive pre-licensure evaluations conducted did not identify an associated risk. The limitations of large Phase III trials have also been

  5. The costs and effectiveness of large Phase III pre-licensure vaccine clinical trials.

    PubMed

    Black, Steven

    2015-01-01

    Prior to the 1980s, most vaccines were licensed based upon safety and effectiveness studies in several hundred individuals. Beginning with the evaluation of Haemophilus influenzae type b conjugate vaccines, much larger pre-licensure trials became common. The pre-licensure trial for Haemophilus influenzae oligosaccharide conjugate vaccine had more than 60,000 children and that of the seven-valent pneumococcal conjugate vaccine included almost 38,000 children. Although trial sizes for both of these studies were driven by the sample size required to demonstrate efficacy, the sample size requirements for safety evaluations of other vaccines have subsequently increased. With the demonstration of an increased risk of intussusception following the Rotashield brand rotavirus vaccine, this trend has continued. However, routinely requiring safety studies of 20,000-50,000 or more participants has two major downsides. First, the cost of performing large safety trials routinely prior to licensure of a vaccine is very large, with some estimates as high at US$200 million euros for one vaccine. This high financial cost engenders an opportunity cost whereby the number of vaccines that a company is willing or able to develop to meet public health needs becomes limited by this financial barrier. The second downside is that in the pre-licensure setting, such studies are very time consuming and delay the availability of a beneficial vaccine substantially. One might argue that in some situations, this financial commitment is warranted such as for evaluations of the risk of intussusception following newer rotavirus vaccines. However, it must be noted that while an increased risk of intussusception was not identified in large pre-licensure studies, in post marketing evaluations an increased risk of this outcome has been identified. Thus, even the extensive pre-licensure evaluations conducted did not identify an associated risk. The limitations of large Phase III trials have also been

  6. Equivalent circuit effects on mode transitions in H{sub 2} inductively coupled plasmas

    SciTech Connect

    Xu, Hui-Jing; Zhao, Shu-Xia Zhang, Yu-Ru; Gao, Fei; Li, Xue-Chun; Wang, You-Nian

    2015-04-15

    It is well known experimentally that the circuit matching network plays an important role in the mode transition behavior of inductively coupled plasmas. To date, however, there have been no reports of numerical models being used to study the role of the matching circuit in the transition process. In this paper, a new two-dimensional self-consistent fluid model that couples the components of an equivalent circuit module is developed to investigate the effects of the equivalent circuit on the mode transition characteristics of an inductively coupled, hydrogen plasma. The equivalent circuit consists of a current source, impedance matching network, reactor impedance, and plasma transferred impedance. The nonlinear coupling of the external circuit with the internal plasma is investigated by adjusting the matching capacitance at a fixed input current. The electron density and temperature as well as the electromagnetic fields all change suddenly, and the E to H mode transition occurs abruptly at a certain matching capacitance as the impedance matching of the external circuit is varied. We also analyze the fields and the plasma characteristics during the transition process, especially for the case of the capacitive E mode.

  7. Spectral analysis of Hall-effect thruster plasma oscillations based on the empirical mode decomposition

    NASA Astrophysics Data System (ADS)

    Kurzyna, J.; Mazouffre, S.; Lazurenko, A.; Albarède, L.; Bonhomme, G.; Makowski, K.; Dudeck, M.; Peradzyński, Z.

    2005-12-01

    Hall-effect thruster plasma oscillations recorded by means of probes located at the channel exit are analyzed using the empirical mode decomposition (EMD) method. This self-adaptive technique permits to decompose a nonstationary signal into a set of intrinsic modes, and acts as a very efficient filter allowing to separate contributions of different underlying physical mechanisms. Applying the Hilbert transform to the whole set of modes allows to identify peculiar events and to assign them a range of instantaneous frequency and power. In addition to 25kHz breathing-type oscillations which are unambiguously identified, the EMD approach confirms the existence of oscillations with instantaneous frequencies in the range of 100-500kHz typical for ion transit-time oscillations. Modeling of high-frequency modes (ν˜10MHz) resulting from EMD of measured wave forms supports the idea that high-frequency plasma oscillations originate from electron-density perturbations propagating azimuthally with the electron drift velocity.

  8. Long-wavelength asymptotics of unstable crossflow modes, including the effect of surface curvature

    NASA Technical Reports Server (NTRS)

    Choudhari, Meelan

    1994-01-01

    Stationary vortex instabilities with wavelengths significantly larger than the thickness of the underlying three-dimensional boundary layer are studied with asymptotic methods. The long-wavelength Rayleigh modes are locally neutral and are aligned with the direction of the local inviscid streamline. For a spanwise wave number Beta much less than 1, the spatial growth rate of these vortices is O(Beta(exp 3/2)). When Beta becomes O(R(exp -1/7)), the viscous correction associated with a thin sublayer near the surface modifies the inviscid growth rate to the leading order. As Beta is further decreased through this regime, viscous effects assume greater significance and dominate the growth-rate behavior. The spatial growth rate becomes comparable to the real part of the wave number when Beta = O(R(exp -1/4)). At this stage, the disturbance structure becomes fully viscous-inviscid interactive and is described by the triple-deck theory. For even smaller values of Beta, the vortex modes become nearly neutral again and align themselves with the direction of the wall-shear stress. Thus, the study explains the progression of the crossflow-vortex structure from the inflectional upper branch mode to nearly neutral long-wavelength modes that are aligned with the wall-shear direction.

  9. Spectral analysis of Hall-effect thruster plasma oscillations based on the empirical mode decomposition

    SciTech Connect

    Kurzyna, J.; Mazouffre, S.; Lazurenko, A.; Albarede, L.; Bonhomme, G.; Makowski, K.; Dudeck, M.; Peradzynski, Z.

    2005-12-15

    Hall-effect thruster plasma oscillations recorded by means of probes located at the channel exit are analyzed using the empirical mode decomposition (EMD) method. This self-adaptive technique permits to decompose a nonstationary signal into a set of intrinsic modes, and acts as a very efficient filter allowing to separate contributions of different underlying physical mechanisms. Applying the Hilbert transform to the whole set of modes allows to identify peculiar events and to assign them a range of instantaneous frequency and power. In addition to 25 kHz breathing-type oscillations which are unambiguously identified, the EMD approach confirms the existence of oscillations with instantaneous frequencies in the range of 100-500 kHz typical for ion transit-time oscillations. Modeling of high-frequency modes ({nu}{approx}10 MHz) resulting from EMD of measured wave forms supports the idea that high-frequency plasma oscillations originate from electron-density perturbations propagating azimuthally with the electron drift velocity.

  10. The effects of sloshing energetic particles on ballooning modes in tokamaks

    NASA Astrophysics Data System (ADS)

    Stotler, D. P.; Berk, H. L.

    1987-05-01

    Distributions that give rise to energetic trapped particle pressures peaked in the ``good curvature'' region of a tokamak (sloshing distributions) are examined in an attempt to find stable regimes for both the magnetohydrodynamic (MHD) and precessional modes. It is the precessional drift destabilization of ballooning modes that inhibits bridging the unstable gap to second stability by the use of deeply trapped energetic particles unless the hot particles have an extremely large energy (˜0.35 MeV for a tokamak like PDX [Phys. Rev. Lett. 49, 326 (1982)]). Unfortunately, our calculations indicate that the sloshing particles do not have a significant stabilizing effect. An analytic treatment shows that stability for the precessional mode can be found only if the sign of the energetic particle magnetic drift frequency can be reversed from its value in vacuum bad curvature without hot species diamagnetism. This is difficult to do in a tokamak because of the destabilizing contribution of the geodesic curvature to the drift frequency. Furthermore, for each of the two sloshing distributions employed (one contains only trapped particles; the other includes trapped and passing particles), a new ``continuum instability'' (where asymptotically along the field line the mode is a propagating plane wave) is found to be driven by geodesic curvature. These results indicate that energetic sloshing particles are not able to bridge the unstable gap to second stability.

  11. Effect of the surface-stimulated mode on the kinetics of homogeneous crystal nucleation in droplets.

    PubMed

    Djikaev, Y S

    2008-07-24

    The thermodynamics of surface-stimulated crystal nucleation demonstrates that if at least one of the facets of the crystal is only partially wettable by its melt, then it is thermodynamically more favorable for the nucleus to form with that facet at the droplet surface rather than within the droplet. So far, however, the kinetic aspects of this phenomenon had not been studied at all. In the present paper, a kinetic theory of homogenous crystal nucleation in unary droplets is proposed by taking into account that a crystal nucleus can form not only in the volume-based mode (with all its facets within the droplet) but also in the surface-stimulated one (with one of its facets at the droplet surface). The theory advocates that even in the surface-stimulated mode crystal nuclei initially emerge (as subcritical clusters) homogeneously in the subsurface layer, not "pseudo-heterogeneously" at the surface. A homogeneously emerged subcritical crystal can become a surface-stimulated nucleus due to density and structure fluctuations. This effect contributes to the total rate of crystal nucleation (as the volume-based mode does). An explicit expression for the total per-particle rate of crystal nucleation is derived. Numerical evaluations for water droplets suggest that the surface-stimulated mode can significantly enhance the per-particle rate of crystal nucleation in droplets as large as 10 microm in radius. Possible experimental verification of the proposed theory is discussed.

  12. Effect of a variable cosmological constant on black hole quasinormal modes

    NASA Astrophysics Data System (ADS)

    Chirenti, Cecilia; Rodrigues, Manuela G.

    2015-10-01

    Many different cosmological models have been proposed to address the cosmological constant problem and the coincidence problem. We compare here four different models that can be used to describe an effective (time-dependent) cosmological constant Λ (z ). A numerical analysis of the Λ (z ) evolution obtained for each model shows that it can be used for distinguishing between all four models. We calculate next the ω (Λ ) frequencies for quasinormal modes of gravitational perturbations of Schwarzschild-de Sitter black holes at different redshifts. Considering that the variation of Λ happens on cosmological time scales, the combined ω (Λ (z )) could be used in principle to track the evolution of the cosmological constant. We quantify the resulting minute frequency shift in the quasinormal mode frequencies and show that the relative frequency shift grows as M2. However, even in a most optimistic scenario with an extremely high mass supermassive black hole there is no prospect for the detection of this effect.

  13. Effect of relativistic acceleration on localized two-mode Gaussian quantum states

    NASA Astrophysics Data System (ADS)

    Ahmadi, Mehdi; Lorek, Krzysztof; Checińska, Agata; Smith, Alexander R. H.; Mann, Robert B.; Dragan, Andrzej

    2016-06-01

    We study how an arbitrary Gaussian state of two localized wave packets, prepared in an inertial frame of reference, is described by a pair of uniformly accelerated observers. We explicitly compute the resulting state for arbitrarily chosen proper accelerations of the observers and independently tuned distance between them. To do so, we introduce a generalized Rindler frame of reference and analytically derive the corresponding state transformation as a Gaussian channel. Our approach provides several new insights into the phenomenon of vacuum entanglement such as the highly nontrivial effect of spatial separation between the observers including sudden death of entanglement. We also calculate the fidelity of the two-mode channel for nonvacuum Gaussian states and obtain bounds on classical and quantum capacities of a single-mode channel. Our framework can be directly applied to any continuous variable quantum information protocol in which the effects of acceleration or gravity cannot be neglected.

  14. Cancellation of drift kinetic effects between thermal and energetic particles on the resistive wall mode stabilization

    NASA Astrophysics Data System (ADS)

    Guo, S. C.; Liu, Y. Q.; Xu, X. Y.; Wang, Z. R.

    2016-07-01

    Drift kinetic stabilization of the resistive wall mode (RWM) is computationally investigated using MHD-kinetic hybrid code MARS-K following the non-perturbative approach (Liu et al 2008 Phys. Plasmas 15 112503), for both reversed field pinch (RFP) and tokamak plasmas. Toroidal precessional drift resonance effects from trapped energetic ions (EIs) and various kinetic resonances between the mode and the guiding center drift motions of thermal particles are included into the self-consistent toroidal computations. The results show cancellation effects of the drift kinetic damping on the RWM between the thermal particles and EIs contributions, in both RFP and tokamak plasmas, even though each species alone can provide damping and stabilize RWM instability by respective kinetic resonances. The degree of cancellation generally depends on the EIs equilibrium distribution, the particle birth energy, as well as the toroidal flow speed of the plasma.

  15. Spectral Splitting Effects and Their Influence to the Performance of Quantum Dot Mode Locked Lasers

    NASA Astrophysics Data System (ADS)

    Mesaritakis, Charis; Syvridis, Dimitris

    In this chapter the multi-wavelength emission capabilities of quantum dot (QD) lasers, due to splitting effects in the ground-state (GS), are analyzed. These emission sub-bands are not related to carrier transitions from different excitation levels like GS/excited-state (ES) emission, but are strongly depended on gain saturation effects. The existence of these sub-bands alongside their wavelength tuning capabilities, have enabled the identification of novel regimes of operation like pulse width narrowing in the presence of dual GS emission, and tunable dual state mode locking. The exploitation of these regimes can allow the deployment of QD mode locked lasers into newly emerging applications both in the telecomm and medical field.

  16. Modeling and analysis of polarization effects in Fourier domain mode-locked lasers.

    PubMed

    Jirauschek, Christian; Huber, Robert

    2015-05-15

    We develop a theoretical model for Fourier domain mode-locked (FDML) lasers in a non-polarization-maintaining configuration, which is the most widely used type of FDML source. This theoretical approach is applied to analyze a widely wavelength-swept FDML setup, as used for picosecond pulse generation by temporal compression of the sweeps. We demonstrate that good agreement between simulation and experiment can only be obtained by including polarization effects due to fiber bending birefringence, polarization mode dispersion, and cross-phase modulation into the theoretical model. Notably, the polarization dynamics are shown to have a beneficial effect on the instantaneous linewidth, resulting in improved coherence and thus compressibility of the wavelength-swept FDML output.

  17. Ferrimagnetic ordering behaviors and compensation temperatures in the FeIIFeIII bimetallic oxalates: Effective-field theory

    NASA Astrophysics Data System (ADS)

    Shi, Xiaoling; Qi, Yang

    2016-08-01

    A mixed spin-2 (FeII) and spin-5/2 (FeIII) ferrimagnetic Ising model on a honeycomb lattice was built to describe the FeII FeIII bimetallic oxalates, and the ferrimagnetic ordering behaviors and compensation temperatures were investigated through the effective-field theory based on Glauber-type stochastic dynamic. It was found that the effects of the interlayer coupling and the single-ion anisotropy contributed to the increase of the critical temperature with growing layer separation and the existence of compensation temperature depending on the organic cation. In particular, the magnetization of the system may show a small discontinuous jump in a certain range of the single-ion anisotropy.

  18. Risk assessment of the emergency processes: Healthcare failure mode and effect analysis

    PubMed Central

    Taleghani, Yasamin Molavi; Rezaei, Fatemeh; Sheikhbardsiri, Hojat

    2016-01-01

    BACKGROUND: Ensuring about the patient’s safety is the first vital step in improving the quality of care and the emergency ward is known as a high-risk area in treatment health care. The present study was conducted to evaluate the selected risk processes of emergency surgery department of a treatment-educational Qaem center in Mashhad by using analysis method of the conditions and failure effects in health care. METHODS: In this study, in combination (qualitative action research and quantitative cross-sectional), failure modes and effects of 5 high-risk procedures of the emergency surgery department were identified and analyzed according to Healthcare Failure Mode and Effects Analysis (HFMEA). To classify the failure modes from the “nursing errors in clinical management model (NECM)”, the classification of the effective causes of error from “Eindhoven model” and determination of the strategies to improve from the “theory of solving problem by an inventive method” were used. To analyze the quantitative data of descriptive statistics (total points) and to analyze the qualitative data, content analysis and agreement of comments of the members were used. RESULTS: In 5 selected processes by “voting method using rating”, 23 steps, 61 sub-processes and 217 potential failure modes were identified by HFMEA. 25 (11.5%) failure modes as the high risk errors were detected and transferred to the decision tree. The most and the least failure modes were placed in the categories of care errors (54.7%) and knowledge and skill (9.5%), respectively. Also, 29.4% of preventive measures were in the category of human resource management strategy. CONCLUSION: “Revision and re-engineering of processes”, “continuous monitoring of the works”, “preparation and revision of operating procedures and policies”, “developing the criteria for evaluating the performance of the personnel”, “designing a suitable educational content for needs of employee”,

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

    ERIC Educational Resources Information Center

    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…

  20. Revisiting the First Galaxies: The Effects of Population III Stars on their Host Galaxies

    NASA Astrophysics Data System (ADS)

    Muratov, Alexander L.; Gnedin, Oleg Y.; Gnedin, Nickolay Y.; Zemp, Marcel

    2013-08-01

    We revisit the formation and evolution of the first galaxies using new hydrodynamic cosmological simulations with the adaptive refinement tree code. Our simulations feature a recently developed model for H2 formation and dissociation, and a star formation recipe that is based on molecular rather than atomic gas. Here, we develop and implement a recipe for the formation of metal-free Population III (Pop III) stars in galaxy-scale simulations that resolve primordial clouds with sufficiently high density. We base our recipe on the results of prior zoom-in simulations that resolved the protostellar collapse in pre-galactic objects. We find the epoch during which Pop III stars dominated the energy and metal budget of the first galaxies to be short-lived. Galaxies that host Pop III stars do not retain dynamical signatures of their thermal and radiative feedback for more than 108 years after the lives of the stars end in pair-instability supernovae, even when we consider the maximum reasonable efficiency of the feedback. Though metals ejected by the supernovae can travel well beyond the virial radius of the host galaxy, they typically begin to fall back quickly, and do not enrich a large fraction of the intergalactic medium. Galaxies with a total mass in excess of 3 × 106 M ⊙ re-accrete most of their baryons and transition to metal-enriched Pop II star formation.

  1. 78 FR 4094 - Effective Date of Requirement for Premarket Approval for Two Class III Preamendments Devices

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-18

    ... the following two class III preamendments devices: Hip joint metal/metal semi- constrained, with a cemented acetabular component, prosthesis; and hip joint metal/metal semi-constrained, with an uncemented.... Hip Joint Metal/Metal Semi-Constrained, With a Cemented Acetabular Component, Prosthesis (21 CFR...

  2. REVISITING THE FIRST GALAXIES: THE EFFECTS OF POPULATION III STARS ON THEIR HOST GALAXIES

    SciTech Connect

    Muratov, Alexander L.; Gnedin, Oleg Y.; Zemp, Marcel; Gnedin, Nickolay Y.

    2013-08-01

    We revisit the formation and evolution of the first galaxies using new hydrodynamic cosmological simulations with the adaptive refinement tree code. Our simulations feature a recently developed model for H{sub 2} formation and dissociation, and a star formation recipe that is based on molecular rather than atomic gas. Here, we develop and implement a recipe for the formation of metal-free Population III (Pop III) stars in galaxy-scale simulations that resolve primordial clouds with sufficiently high density. We base our recipe on the results of prior zoom-in simulations that resolved the protostellar collapse in pre-galactic objects. We find the epoch during which Pop III stars dominated the energy and metal budget of the first galaxies to be short-lived. Galaxies that host Pop III stars do not retain dynamical signatures of their thermal and radiative feedback for more than 10{sup 8} years after the lives of the stars end in pair-instability supernovae, even when we consider the maximum reasonable efficiency of the feedback. Though metals ejected by the supernovae can travel well beyond the virial radius of the host galaxy, they typically begin to fall back quickly, and do not enrich a large fraction of the intergalactic medium. Galaxies with a total mass in excess of 3 Multiplication-Sign 10{sup 6} M{sub Sun} re-accrete most of their baryons and transition to metal-enriched Pop II star formation.

  3. The Quest for Relevance: Effective College Teaching. Volume III. The Social Sciences.

    ERIC Educational Resources Information Center

    American Association for Higher Education, Washington, DC.

    Responding to a widely expressed discontent about college teaching shared by students, faculty and administrators, representatives of national professional and higher educational associations formed a committee to study means of revitalizing and reorienting instruction. Each contributor in Volume III, selected for his outstanding teaching skills…

  4. Polarization mode coupling and related effects in fiber Bragg grating inscribed in polarization maintaining fiber.

    PubMed

    Zhao, Yanshuang; Sun, Bo; Liu, Yanlei; Ren, Jing; Zhang, Jianzhong; Yang, Jun; Canning, John; Peng, G D; Yuan, Libo

    2016-01-11

    Polarization mode coupling (PMC) and related effects from writing fiber Bragg gratings in polarization maintaining fiber (FBGs-in-PMF) are observed experimentally for the first time by optical fiber coherence domain polarimetry (OCDP) using a broadband light source. PMC is another useful aspect of FBG-in-PMF besides Bragg wavelength and its possible potential is evaluated and discussed. A localized and long range temperature measurement based on the PMC and Bragg wavelength is given as an example. PMID:26832291

  5. The effect of periodic wavy profile on suppressing window multipactor under arbitrary electromagnetic mode

    SciTech Connect

    Chang, C.; Liu, Y. S.; Chen, C. H.; Guo, L. T.; Li, S.; Wu, X. L.; Verboncoeur, J.

    2015-01-05

    The three-dimensional periodic ripple profile with each unit of rotational symmetric surface is proposed to suppress multipactor for arbitrary electromagnetic mode with any polarization. The field distribution and multipactor electron dynamics on the wavy surface are studied to illustrate the multipactor inhibition mechanism. High power microwave experiment was conducted to demonstrate the effect of wavy surface on significantly improving the window power capacity.

  6. Effect of water vapor on the performance of glass RPCs in avalanche mode operation

    NASA Astrophysics Data System (ADS)

    Raveendrababu, K.; Behera, P. K.; Satyanarayana, B.; Mukhopadhayay, S.; Majumdar, N.

    2016-08-01

    We studied the effect of water vapor on the performance of glass Resistive Plate Chambers (RPCs) in the avalanche mode operation. Controlled amount of water vapor was added to the RPC gas mixture that has C2H2F4 as the major component. The deterioration in the performance of RPC was observed while operating with the wet gas and recovered after switching to the standard gas.

  7. Preliminary Failure Modes and Effects Analysis of the US DCLL Test Blanket Module

    SciTech Connect

    Lee C. Cadwallader

    2007-08-01

    This report presents the results of a preliminary failure modes and effects analysis (FMEA) of a small tritium-breeding test blanket module design for the International Thermonuclear Experimental Reactor. The FMEA was quantified with “generic” component failure rate data, and the failure events are binned into postulated initiating event families and frequency categories for safety assessment. An appendix to this report contains repair time data to support an occupational radiation exposure assessment for test blanket module maintenance.

  8. Preliminary Failure Modes and Effects Analysis of the US DCLL Test Blanket Module

    SciTech Connect

    Lee C. Cadwallader

    2010-06-01

    This report presents the results of a preliminary failure modes and effects analysis (FMEA) of a small tritium-breeding test blanket module design for the International Thermonuclear Experimental Reactor. The FMEA was quantified with “generic” component failure rate data, and the failure events are binned into postulated initiating event families and frequency categories for safety assessment. An appendix to this report contains repair time data to support an occupational radiation exposure assessment for test blanket module maintenance.

  9. Preliminary Failure Modes and Effects Analysis of the US Massive Gas Injection Disruption Mitigation System Design

    SciTech Connect

    Lee C. Cadwallader

    2013-10-01

    This report presents the results of a preliminary failure modes and effects analysis (FMEA) of a candidate design for the ITER Disruption Mitigation System. This candidate is the Massive Gas Injection System that provides machine protection in a plasma disruption event. The FMEA was quantified with “generic” component failure rate data as well as some data calculated from operating facilities, and the failure events were ranked for their criticality to system operation.

  10. Spatiotemporal Patterns of a Predator-Prey System with an Allee Effect and Holling Type III Functional Response

    NASA Astrophysics Data System (ADS)

    Li, Yuanyuan; Wang, Jinfeng

    A diffusive Gause type predator-prey system with Allee effect in prey growth and Holling type III response subject to Neumann boundary conditions is investigated. Existence of nonconstant positive steady state solutions is proved by Leray-Schauder degree theory and bifurcation theory. Global stability of the positive equilibrium of the system is also investigated. Moreover, bifurcations of spatially homogeneous and nonhomogeneous periodic solutions are analyzed. Our rigorous results justify some recent ecological observations.

  11. Metal complexes of 3-(4-bromophenyl)-1-pyridin-2-ylprop-2-en-1-one thiosemicarbazone: cytotoxic activity and investigation on the mode of action of the gold(III) complex.

    PubMed

    Sâmia, Luciana B P; Parrilha, Gabrieli L; Da Silva, Jeferson G; Ramos, Jonas P; Souza-Fagundes, Elaine M; Castelli, Silvia; Vutey, Venn; Desideri, Alessandro; Beraldo, Heloisa

    2016-06-01

    Complexes [Au(PyCT4BrPh)Cl]Cl (1), [Pt(PyCT4BrPh)Cl]0.5KCl (2), and [Pd(PyCT4BrPh)Cl]KCl (3) were obtained with 3-(4-bromophenyl)-1-pyridin-2-ylprop-2-en-1-one thiosemicarbazone (HPyCT4BrPh). Although complexes (2) and (3) did not exhibit potent cytotoxic activity, HPyCT4BrPh and its gold(III) complex (1) proved to be highly cytotoxic against HL-60 (human promyelocytic leukemia) and THP-1 (human monocytic leukemia) cells, and against MDA-MB 231 and MCF-7 (human breast adenocarcinoma) solid tumor cells. Except for HL-60 cells, upon coordination to gold(III) a 2- to 3-fold increase in the cytotoxic effect was observed. An investigation on the possible biological targets of the gold(III) complex was carried out. Complex (1) but not the free thiosemicarbazone inhibits the enzymatic activity of thioredoxin reductase (TrxR). The affinity of 1 for TrxR suggests metal binding to a selenol residue in the active site of the enzyme. While HPyCT4BrPh was inactive, 1 was able to inhibit topoisomerase IB (Topo IB) activity. Hence, inhibition of TrxR and Topo IB could contribute to the mechanism of cytotoxic action of complex (1).

  12. The Effects of Helmet Weight on Hybrid III Head and Neck Responses by Comparing Unhelmeted and Helmeted Impacts.

    PubMed

    Jadischke, Ron; Viano, David C; McCarthy, Joe; King, Albert I

    2016-10-01

    Most studies on football helmet performance focus on lowering head acceleration-related parameters to reduce concussions. This has resulted in an increase in helmet size and mass. The objective of this paper was to study the effect of helmet mass on head and upper neck responses. Two independent test series were conducted. In test series one, 90 pendulum impact tests were conducted with four different headform and helmet conditions: unhelmeted Hybrid III headform, Hybrid III headform with a football helmet shell, Hybrid III headform with helmet shell and facemask, and Hybrid III headform with the helmet and facemask with mass added to the shell (n = 90). The Hybrid III neck was used for all the conditions. For all the configurations combined, the shell only, shell and facemask, and weighted helmet conditions resulted in 36%, 43%, and 44% lower resultant head accelerations (p < 0.0001), respectively, when compared to the unhelmeted condition. Head delta-V reductions were 1.1%, 4.5%, and 4.4%, respectively. In contrast, the helmeted conditions resulted in 26%, 41%, and 49% higher resultant neck forces (p < 0.0001), respectively. The increased neck forces were dominated by neck tension. In test series two, testing was conducted with a pneumatic linear impactor (n = 178). Fourteen different helmet makes and models illustrate the same trend. The increased neck forces provide a possible explanation as to why there has not been a corresponding reduction in concussion rates despite improvements in helmets ability to reduce head accelerations.

  13. The Effects of Helmet Weight on Hybrid III Head and Neck Responses by Comparing Unhelmeted and Helmeted Impacts.

    PubMed

    Jadischke, Ron; Viano, David C; McCarthy, Joe; King, Albert I

    2016-10-01

    Most studies on football helmet performance focus on lowering head acceleration-related parameters to reduce concussions. This has resulted in an increase in helmet size and mass. The objective of this paper was to study the effect of helmet mass on head and upper neck responses. Two independent test series were conducted. In test series one, 90 pendulum impact tests were conducted with four different headform and helmet conditions: unhelmeted Hybrid III headform, Hybrid III headform with a football helmet shell, Hybrid III headform with helmet shell and facemask, and Hybrid III headform with the helmet and facemask with mass added to the shell (n = 90). The Hybrid III neck was used for all the conditions. For all the configurations combined, the shell only, shell and facemask, and weighted helmet conditions resulted in 36%, 43%, and 44% lower resultant head accelerations (p < 0.0001), respectively, when compared to the unhelmeted condition. Head delta-V reductions were 1.1%, 4.5%, and 4.4%, respectively. In contrast, the helmeted conditions resulted in 26%, 41%, and 49% higher resultant neck forces (p < 0.0001), respectively. The increased neck forces were dominated by neck tension. In test series two, testing was conducted with a pneumatic linear impactor (n = 178). Fourteen different helmet makes and models illustrate the same trend. The increased neck forces provide a possible explanation as to why there has not been a corresponding reduction in concussion rates despite improvements in helmets ability to reduce head accelerations. PMID:27456840

  14. BetaIII-tubulin induces paclitaxel resistance in association with reduced effects on microtubule dynamic instability.

    PubMed

    Kamath, Kathy; Wilson, Leslie; Cabral, Fernando; Jordan, Mary Ann

    2005-04-01

    The development of resistance to paclitaxel in tumors is one of the most significant obstacles to successful therapy. Overexpression of the betaIII-tubulin isotype has been associated with paclitaxel resistance in a number of cancer cell lines and in tumors, but the mechanism of resistance has remained unclear. Paclitaxel inhibits cancer cell proliferation by binding to the beta-subunit of tubulin in microtubules and suppressing microtubule dynamic instability, leading to mitotic arrest and cell death. We hypothesized that betaIII-tubulin overexpression induces resistance to paclitaxel either by constitutively enhancing microtubule dynamic instability in resistant cells or by rendering the microtubules less sensitive to the suppression of dynamics by paclitaxel. Using Chinese hamster ovary cells that inducibly overexpress either betaI- or betaIII-tubulin, we analyzed microtubule dynamic instability during interphase by microinjection of rhodamine-labeled tubulin and time-lapse fluorescence microscopy. In the absence of paclitaxel, there were no differences in any aspect of dynamic instability between the two beta-tubulin-overexpressing cell types. However, in the presence of 150 nm paclitaxel, dynamic instability was suppressed to a significantly lesser extent (suppressed only 12%) in cells overexpressing betaIII-tubulin than in cells overexpressing similar levels of betaI-tubulin (suppressed 47%). The results suggest that overexpression of betaIII-tubulin induces paclitaxel resistance by reducing the ability of paclitaxel to suppress microtubule dynamics. The results also suggest that endogenous regulators of microtubule dynamics may differentially interact with individual tubulin isotypes, supporting the idea that differential expression of tubulin isotypes has functional consequences in cells.

  15. Modeling the Effect of Multiple Matrix Cracking Modes on Cyclic Hysteresis Loops of 2D Woven Ceramic-Matrix Composites

    NASA Astrophysics Data System (ADS)

    Longbiao, Li

    2016-08-01

    In this paper, the effect of multiple matrix cracking modes on cyclic loading/unloading hysteresis loops of 2D woven ceramic-matrix composites (CMCs) has been investigated. The interface slip between fibers and the matrix existed in matrix cracking mode 3 and mode 5, in which matrix cracking and interface debonding occurred in longitudinal yarns, are considered as the major reason for hysteresis loops of 2D woven CMCs. The effects of fiber volume content, peak stress, matrix crack spacing, interface properties, matrix cracking mode proportion and interface wear on interface slip and hysteresis loops have been analyzed. The cyclic loading/unloading hysteresis loops of 2D woven SiC/SiC composite corresponding to different peak stresses have been predicted using the present analysis. It was found that the damage parameter, i.e., the proportion of matrix cracking mode 3 in the entire cracking modes of the composite, increases with increasing peak stress.

  16. Understanding the effect of resonant magnetic perturbations on tearing mode dynamics

    SciTech Connect

    Hu, Qiming; Rao, Bo; Ding, Yonghua; Zhuang, Ge; Jin, Wei; Hu, Xiwei; Yu, Q.

    2013-09-15

    Numerical understandings of the effect of resonant magnetic perturbations (RMPs) on 2/1 tearing mode (TM) dynamics observed on J-TEXT tokamak (Hu et al. Nucl. Fusion 52, 083011 (2012)) are presented in this paper. The non-uniform mode rotation frequency, modulated by electromagnetic force (F{sub em}) and viscous force (F{sub vs}), results in the applied RMPs contributing both net stabilizing and braking effect on TM. Numerical evaluation based on analytical theory shows the applied RMP contributes a dominant stabilizing effect, which is responsible for the suppression of TM. The dynamics of the first discovered small locked island are investigated. It is found that the island is locked at the stabilizing phase and the saturated island width is less than the linear layer width. The simulated Mirnov signal indicates the small locked island is likely to be the complete suppression case observed in experiments. Associated with the application of RMP, the shape of Mirnov signal deviates from sinusoidal before mode locking, which is explained by numerical modeling. The comparisons between the numerical and experimental results are in good agreement phenomenally.

  17. Impurity Effects on Caroli-de Gennes-Matricon Mode in Vortex Core in Superconductors

    NASA Astrophysics Data System (ADS)

    Masaki, Yusuke; Kato, Yusuke

    2016-01-01

    We have developed a scheme of Gor'kov Green's functions to treat the impurity effects on the Caroli-de Gennes-Matricon (CdGM) mode in superconductors (SCs) by improving the Kopnin-Kravtsov scheme with respect to the coherence factors and applicability to various SCs. We can study the impurity effects while keeping the discreteness of the energy spectrum, in contrast to the quasiclassical theory. We can thus apply this scheme to SCs with a small quasiclassical parameter kFξ0 (which is the product of the Fermi wavenumber kF and the coherence length ξ0 in a pure SC at zero temperature) and/or in the superclean regime Δ miniτ ≫ 1 (Δmini and τ denote, respectively, the level spacing of the CdGM mode called the minigap and the relaxation time for the CdGM mode and we take ħ = 1). We investigate the impurity effects as a white noise for a vortex in an s-wave SC and two types of vortex in a chiral p-wave SC for various values of the quasiclassical parameter and impurity strength (from the moderately clean regime to the superclean regime) and confirm the validity of this scheme.

  18. Failure mode and effects analysis using intuitionistic fuzzy hybrid weighted Euclidean distance operator

    NASA Astrophysics Data System (ADS)

    Liu, Hu-Chen; Liu, Long; Li, Ping

    2014-10-01

    Failure mode and effects analysis (FMEA) has shown its effectiveness in examining potential failures in products, process, designs or services and has been extensively used for safety and reliability analysis in a wide range of industries. However, its approach to prioritise failure modes through a crisp risk priority number (RPN) has been criticised as having several shortcomings. The aim of this paper is to develop an efficient and comprehensive risk assessment methodology using intuitionistic fuzzy hybrid weighted Euclidean distance (IFHWED) operator to overcome the limitations and improve the effectiveness of the traditional FMEA. The diversified and uncertain assessments given by FMEA team members are treated as linguistic terms expressed in intuitionistic fuzzy numbers (IFNs). Intuitionistic fuzzy weighted averaging (IFWA) operator is used to aggregate the FMEA team members' individual assessments into a group assessment. IFHWED operator is applied thereafter to the prioritisation and selection of failure modes. Particularly, both subjective and objective weights of risk factors are considered during the risk evaluation process. A numerical example for risk assessment is given to illustrate the proposed method finally.

  19. Hydration effects on the barrier function of stratum corneum lipids: Raman analysis of ceramides 2, III and 5.

    PubMed

    Tfayli, Ali; Jamal, Dima; Vyumvuhore, Raoul; Manfait, Michel; Baillet-Guffroy, Arlette

    2013-11-01

    The stratum corneum is the outermost layer of the skin; its barrier function is highly dependent on the composition and the structure as well as the organization of lipids in its extracellular matrix. Ceramides, free fatty acids and cholesterol represent the major lipid classes present in this matrix. They play an important role in maintaining the normal hydration levels required for the normal physiological function. Despite the advancement in the understanding of the structure, composition and the function of the stratum corneum (SC), the concern of "dry skin" remains important in dermatology and care research. Most studies focus on the quantification of water in the skin using different techniques including Raman spectroscopy, while the studies that investigate the effect of hydration on the quality of the barrier function of the skin are limited. Raman spectroscopy provides structural, conformational and organizational information that could help elucidate the effect of hydration on the barrier function of the skin. In order to assess the effect of relative humidity on the lipid barrier function; we used Raman spectroscopy to follow-up the evolution of the conformation and the organization of three synthetic ceramides (CER) differing from each other by the nature of their polar heads (sphingosine, phytosphingosine and α hydroxyl sphingosine), CER 2, III and 5 respectively. CER III and 5 showed a more compact and ordered organization with stronger polar interactions at intermediate relative humidity values, while CER 2 showed opposite tendencies to those observed with CER III and 5.

  20. U(SMes*)n, (n = 3, 4) and Ln(SMes*)3 (Ln = La, Ce, Pr, Nd): lanthanide(III)/actinide(III) differentiation in agostic interactions and an unprecedented eta3 ligation mode of the arylthiolate ligand, from X-ray diffraction and DFT analysis.

    PubMed

    Roger, Mathieu; Barros, Noémi; Arliguie, Thérèse; Thuéry, Pierre; Maron, Laurent; Ephritikhine, Michel

    2006-07-12

    Reaction of U(NEt(2))(4) with HS-2,4,6-(t)Bu(3)C(6)H(2) (HSMes) gave U(SMes)(3)(NEt(2))(py) (1), whereas similar treatment of U[N(SiMe(3))SiMe(2)CH(2)][N(SiMe(3))(2)](2) afforded U(SMes)[N(SiMe(3))(2)](3) (2) and U(SMes)(3)[N(SiMe(3))(2)]. The first neutral homoleptic uranium(IV) thiolate to have been crystallographically characterized, U(SMes)(4) (4), was isolated from the reaction of U(BH(4))(4) and KSMes. The first homoleptic thiolate complex of uranium(III), U(SMes)(3) (5), was synthesized by protonolysis of U[N(SiMe(3))(2)](3) with HSMes in cyclohexane. The crystal structure of 5 exhibits the novel eta(3) ligation mode for the arylthiolate ligand. Comparison of the crystal structure of 5 with those of the isomorphous lanthanide congeners Ln(SMes)(3) (Ln = La, Ce, Pr, and Nd) indicates that the U-S, U-C(ipso)(), and U-C(ortho)() bond lengths are shorter than the corresponding ones in the 4f-element analogues, when taking into account the variation in the ionic radii of the metals. The distance between the uranium and the carbon atoms involved in the U...H-C epsilon agostic interaction of each thiolate ligand is shorter, by approximately 0.05 A, than that expected from a purely ionic bonding model. The lanthanide(III)/actinide(III) differentiation was analyzed by density functional theory (DFT). The nature of the M-S bond is shown to be ionic strongly polarized at the sulfur for M = U and iono-covalent (i.e. strongly ionic with low orbital interaction), for M = Ln. The strength of the U...H-C epsilon agostic interaction is proposed to be controlled by the maximization of the interaction between U(+) and S(-) under steric constraints. The eta(3) ligation mode of the arylthiolate ligand is also obtained from DFT.

  1. Tip Effect of the Tapping Mode of Atomic Force Microscope in Viscous Fluid Environments.

    PubMed

    Shih, Hua-Ju; Shih, Po-Jen

    2015-01-01

    Atomic force microscope with applicable types of operation in a liquid environment is widely used to scan the contours of biological specimens. The contact mode of operation allows a tip to touch a specimen directly but sometimes it damages the specimen; thus, a tapping mode of operation may replace the contact mode. The tapping mode triggers the cantilever of the microscope approximately at resonance frequencies, and so the tip periodically knocks the specimen. It is well known that the cantilever induces extra liquid pressure that leads to drift in the resonance frequency. Studies have noted that the heights of protein surfaces measured via the tapping mode of an atomic force microscope are ~25% smaller than those measured by other methods. This discrepancy may be attributable to the induced superficial hydrodynamic pressure, which is worth investigating. In this paper, we introduce a semi-analytical method to analyze the pressure distribution of various tip geometries. According to our analysis, the maximum hydrodynamic pressure on the specimen caused by a cone-shaped tip is ~0.5 Pa, which can, for example, pre-deform a cell by several nanometers in compression before the tip taps it. Moreover, the pressure calculated on the surface of the specimen is 20 times larger than the pressure without considering the tip effect; these results have not been motioned in other papers. Dominating factors, such as surface heights of protein surface, mechanical stiffness of protein increasing with loading velocity, and radius of tip affecting the local pressure of specimen, are also addressed in this study. PMID:26225979

  2. Tip Effect of the Tapping Mode of Atomic Force Microscope in Viscous Fluid Environments.

    PubMed

    Shih, Hua-Ju; Shih, Po-Jen

    2015-07-28

    Atomic force microscope with applicable types of operation in a liquid environment is widely used to scan the contours of biological specimens. The contact mode of operation allows a tip to touch a specimen directly but sometimes it damages the specimen; thus, a tapping mode of operation may replace the contact mode. The tapping mode triggers the cantilever of the microscope approximately at resonance frequencies, and so the tip periodically knocks the specimen. It is well known that the cantilever induces extra liquid pressure that leads to drift in the resonance frequency. Studies have noted that the heights of protein surfaces measured via the tapping mode of an atomic force microscope are ~25% smaller than those measured by other methods. This discrepancy may be attributable to the induced superficial hydrodynamic pressure, which is worth investigating. In this paper, we introduce a semi-analytical method to analyze the pressure distribution of various tip geometries. According to our analysis, the maximum hydrodynamic pressure on the specimen caused by a cone-shaped tip is ~0.5 Pa, which can, for example, pre-deform a cell by several nanometers in compression before the tip taps it. Moreover, the pressure calculated on the surface of the specimen is 20 times larger than the pressure without considering the tip effect; these results have not been motioned in other papers. Dominating factors, such as surface heights of protein surface, mechanical stiffness of protein increasing with loading velocity, and radius of tip affecting the local pressure of specimen, are also addressed in this study.

  3. Energetic Particle Effects Can Explain the Low Frequency of Alfvin Modes in the DIII-D Tokamak

    SciTech Connect

    Gorelenkov, N.N.; Heidbrink, W.W.

    2001-01-31

    During beam injection in the DIII-D tokamak, modes with lower frequencies than expected for toroidicity-induced Alfvin eigenmodes (TAE) are often observed. We present the analysis of one of these ''beta-induced Alfvin eigenmodes'' (BAE) with a high-n stability code HINST that includes the effect of the energetic ions on the mode frequency. It shows that the ''BAE'' could be the theoretically predicted resonant-TAE (RTAE), which is also called an energetic-particle mode (EPM).

  4. SAGE III

    Atmospheric Science Data Center

    2016-06-15

    SAGE III Data and Information The Stratospheric Aerosol and Gas ... on the spacecraft. SAGE III produced L1 and L2 scientific data from 5/07/2002 until 12/31/2005. The flight of the second instrument is as ... Guide Documents:  Project Guide Data Products User's Guide  (PDF) Relevant Documents:  ...

  5. Application of Failure Mode and Effects Analysis to Intraoperative Radiation Therapy Using Mobile Electron Linear Accelerators

    SciTech Connect

    Ciocca, Mario; Cantone, Marie-Claire; Veronese, Ivan; Cattani, Federica; Pedroli, Guido; Molinelli, Silvia; Vitolo, Viviana; Orecchia, Roberto

    2012-02-01

    Purpose: Failure mode and effects analysis (FMEA) represents a prospective approach for risk assessment. A multidisciplinary working group of the Italian Association for Medical Physics applied FMEA to electron beam intraoperative radiation therapy (IORT) delivered using mobile linear accelerators, aiming at preventing accidental exposures to the patient. Methods and Materials: FMEA was applied to the IORT process, for the stages of the treatment delivery and verification, and consisted of three steps: 1) identification of the involved subprocesses; 2) identification and ranking of the potential failure modes, together with their causes and effects, using the risk probability number (RPN) scoring system, based on the product of three parameters (severity, frequency of occurrence and detectability, each ranging from 1 to 10); 3) identification of additional safety measures to be proposed for process quality and safety improvement. RPN upper threshold for little concern of risk was set at 125. Results: Twenty-four subprocesses were identified. Ten potential failure modes were found and scored, in terms of RPN, in the range of 42-216. The most critical failure modes consisted of internal shield misalignment, wrong Monitor Unit calculation and incorrect data entry at treatment console. Potential causes of failure included shield displacement, human errors, such as underestimation of CTV extension, mainly because of lack of adequate training and time pressures, failure in the communication between operators, and machine malfunctioning. The main effects of failure were represented by CTV underdose, wrong dose distribution and/or delivery, unintended normal tissue irradiation. As additional safety measures, the utilization of a dedicated staff for IORT, double-checking of MU calculation and data entry and finally implementation of in vivo dosimetry were suggested. Conclusions: FMEA appeared as a useful tool for prospective evaluation of patient safety in radiotherapy. The

  6. Mechanistic investigation of food effect on disintegration and dissolution of BCS class III compound solid formulations: the importance of viscosity.

    PubMed

    Radwan, Asma; Amidon, Gordon L; Langguth, Peter

    2012-10-01

    A negative food effect, i.e. a decrease in bioavailability upon the co-administration of compounds together with food, has been attributed particularly with high solubility/low permeability compounds (BCS class III). Different mechanisms have been proposed including intestinal dilution leading to a lower concentration gradient across the intestinal wall as well as binding of the active pharmaceutical ingredient to food components in the intestine and thereby decreasing the fraction of the dose available for absorption. These mechanisms refer primarily to the compound and not to the dosage form. An increase in viscosity of the dissolution fluid will in particular affect the absorption of BCS type III compounds with preferential absorption in the upper small intestine if the API release is delayed from the dosage form. The present study demonstrated that the increase in viscosity of the dissolution medium, following ingestion of a solid meal, may drastically reduce disintegration and dissolution. For that purpose the viscosity of the standard FDA meal was determined and simulated by solutions of HPMC in buffer. As model formulations, three commercially available tablets containing trospium chloride, a BCS class III m-cholinoreceptor antagonist was used. Trospium chloride drug products have been described to undergo a negative food effect of more than 80% following ingestion with food. The tablets showed prolonged disintegration times and reduced dissolution rates in viscous media, which could be attributed to changes in the liquid penetration rates. The effect was particularly significant for film-coated tablets relative to uncoated dosage forms. The results show the necessity of considering media viscosity when designing in vitro models of drug release for BCS type III drug formulations.

  7. Properties of Higher Plant Mitochondria. III. Effects of Respiratory Inhibitors 1

    PubMed Central

    Ikuma, Hiroshi; Bonner, Walter D.

    1967-01-01

    The effects of representative respiratory inhibitors were investigated on the coupled respiration of mung bean mitochondria using succinate and l-malate as substrates. The inhibitors studied were: (I) malonate, (II) amytal and rotenone, (III) antimycin A and 2-n-nonyl-4-hydroxyquinoline N-oxide (NOQNO), and (IV) cyanide and azide. Malonate inhibition of succinate oxidation follows a classical type of competitive inhibition with an inhibitor dissociation constant of 0.13 mm. There is no inhibition detectable when malate is used as substrate. In contrast to animal mitochondria, amytal is capable of inhibiting 20 to 40% of succinate oxidation and 90 to 100% of malate oxidation, but inhibition due to rotenone amounts to only 0 to 20% of succinate oxidation and 40 to 50% of malate oxidation. The half-maximal inhibition caused by amytal occurs at 2 to 2.5 mm and that by rotenone at 3 mμmoles/mg protein. The maximal inhibition caused by either antimycin A or NOQNO is 70 to 80% of the state 3 respiration. Very little inhibition was observed on the state 4 respiration, and both inhibitors were capable of titrating stoichiometrically with mitochondrial protein with identical titers, 0.22 mμmoles/mg protein for half-maximal inhibition. They differ, however, in that NOQNO does uncouple oxidative phosphorylation in mung bean mitochondria, but antimycin A does not do so. Both cyanide and azide inhibit the state 3 rate 65 to 80%. Inhibition of state 4 respiration can be up to 50% by cyanide, while almost none by azide. Uncoupling action was noted with cyanide, but very little with azide. It is concluded that the second state 3 rate of succinate oxidation includes 80% succinoxidase, the remaining 20% being contributed by the NADH pathway. Malate oxidation apparently does not involve succinoxidase. Malate oxidation is completely sensitive to amytal, but only 50% inhibited by rotenone. A difference between animal and plant mitochondria appears to be in the flavoproteins associated

  8. Plasma Modes

    NASA Astrophysics Data System (ADS)

    Dubin, D. H. E.

    This chapter explores several aspects of the linear electrostatic normal modes of oscillation for a single-species non-neutral plasma in a Penning trap. Linearized fluid equations of motion are developed, assuming the plasma is cold but collisionless, which allow derivation of the cold plasma dielectric tensor and the electrostatic wave equation. Upper hybrid and magnetized plasma waves in an infinite uniform plasma are described. The effect of the plasma surface in a bounded plasma system is considered, and the properties of surface plasma waves are characterized. The normal modes of a cylindrical plasma column are discussed, and finally, modes of spheroidal plasmas, and finite temperature effects on the modes, are briefly described.

  9. Investigation of magneto-optical effects on properties of surface modes in one dimensional magnetized plasma photonic crystals

    NASA Astrophysics Data System (ADS)

    Shukla, Shikha; Prasad, Surendra; Singh, Vivek

    2016-09-01

    We have studied the properties of surface modes on one dimensional magnetized plasma photonic crystals in two configurations: Faraday and Voigt configurations. The results have been demonstrated by using the transfer matrix method and employing boundary conditions for TE and TM modes, respectively. For the Voigt effect, only the TM mode is considered because the TE modes under the influence of external magnetic field have the same properties as un-magnetized plasma. The influence of external magnetic field has been studied for three cases, i.e., TE left circular polarization, TE right circular polarization, and TM surface modes. It is shown that the properties of surface modes can be tuned correspondingly by changing the cap layer thickness, wave vector, and external magnetic field in the desired photonic band gap. The results show that collision frequency has a negligible effect on surface modes. A new type of wave called Fano mode has been reported for the Voigt effect for the TM mode in the first band gap. Proof of its existence has been demonstrated in the present paper.

  10. Kinetic effects on geodesic acoustic mode from combined collisions and impurities

    SciTech Connect

    Yang, Shangchuan; Xie, Jinlin Liu, Wandong

    2015-04-15

    The dispersion relation for geodesic acoustic mode (GAM) is derived by applying a gyrokinetic model that accounts for the effects from both collisions and impurities. Based on the dispersion relation, an analysis is performed for the non-monotonic behavior of GAM damping versus the characteristic collision rate at various impurity levels. As the effective charge increases, the maximum damping rate is found to shift towards lower collision rates, nearer to the parameter range of a typical tokamak edge plasma. The relative strengths of ion-ion and impurity-induced collision effects, which are illustrated by numerical calculations, are found to be comparable. Impurity-induced collisions help decrease the frequency of GAM, while their effects on the damping rate are non-monotonic, resulting in a weaker total damping in the high collision regime. The results presented suggest considering collision effects as well as impurity effects in GAM analysis.

  11. Low-frequency modes and nonbarotropic effects in pseudo-Newtonian accretion disks

    NASA Technical Reports Server (NTRS)

    Ipser, James R.

    1994-01-01

    A recently developed formalism is used to reexamine the question of the existence of hydrodynamical modes that pulsate with very low frequencies in the inner regions of accretion disks. The formalism is valid in an exact sense for the adiabatic pulsations of rotating Newtonian fluids that are generally nonbarotropic (such as those with 'nonadiabatic temperature gradients,' for example), and hence its application in the present context represents an improvement over previous analyses that are more approximate. The formalism is applied to thin non-self-gravitating disks, with the gravitational potential of the central source modified in the usual way in order to simulate relativistic effects. In the barotropic limit, the analyses indicate that in many cases nearly Keplerian disks exhibit nonaxisymmetric modes of pulsation that are trapped in the inner disk regions, with pulsation periods much longer than the dynamical timescale. These results are similar to those of earlier calculations that assume disks pulsate without changing the temperature distribution. A method is developed for including lowest order nonbarotropic effects. Previous analyses have been incapable of accurately treating the nonbarotropic regime. The application of the present method to the low-frequency modes reveals that, due to unexpected cancellations among terms, the nonbarotropic correction to the pusation frequency omega is only of order tilde-omega(sub BV exp 2) omega, where tilde-omega(sub BV) is the appropriate dimensionless Brunt-Vaisala frequency. This correction is much smaller than the expected correction of order tilde-omega(sub BV) Omega, where Omega is the rotation angular velocity. The important conclusion drawn from this is that nonbarotropic corrections are generally small and hence that low-frequency modes persist into the nonbarotropic regime. For disk temperatures appropriate to X-ray emission, the adiabatic frequencies of trapped modes are of the same order as the frequencies

  12. Collision effects on high-n ballooning modes with a full Lorentz collision operator

    NASA Astrophysics Data System (ADS)

    Liu, Jianxun; Chen, Shaoyong; Tang, Changjian

    2012-02-01

    The dispersion relation for high-n ballooning modes is obtained from the customary drift gyro-kinetic equation employing the energy-dependent Lorenz collision operator. There are significant differences between our results and those with the Krook collision operator. The present results show that collision seems to have much weaker stabilizing effects, if any, on the high-n ballooning modes than those with the Krook collision operator when the collisionality, υ*e, is smaller than a critical value. However, contrary to the phenomenon, the collision shows strong stabilizing effects on the ballooning mode once the collisionality exceeds a critical value. These differences are supposed to arise from boundary layer behaviour which refers to the electron perturbation at the boundary between trapped and passing electrons in velocity space, but the physical process cannot be described by non-conserving Krook collision operators. This destabilizing mechanism of boundary layer behaviour is discussed in this paper. In addition, the critical value shows a considerably strong dependence on ηe (ηe ≡ d ln Te/d ln Ne).

  13. Systematic effects of Alfv'en waves on whistler mode transmission

    NASA Astrophysics Data System (ADS)

    Skiff, Fred; Schroeder, J.; Drake, J. D.; Howes, G. G.; Kletzing, C. A.; Carter, T. A.; Dorfman, S.; Auerbach, D.

    2012-10-01

    We study the systematic effects on whistler mode transmission measurements caused by shear Alfv'en waves in the LAPD plasma device with the goal of detecting the plasma dielectric response and electron acceleration along the magnetic field. Alfv'en waves with δB/B˜ 10-5 are generated using an arbitrary spatial waveform antenna adjusted to produce plane waves in the central region of the plasma with a perpendicular wavelength comparable to the collisionless skin depth. In the overdense (φp/φc˜ 2-3) LAPD plasma with B=1800 G, the whistler mode is the only wave propagating parallel to the magnetic field just below the electron cyclotron frequency. Whistler mode absorption has previously been used successfully to measure the electron temperature, but here we observe systematic changes to the whistler transmission signal caused by the Alfv'en wave. We will discuss the problems of separating out the effect of changes in the plasma density (including ducting) with measurements of the perturbed electron velocity distribution.

  14. Remembered study mode: support for the distinctiveness account of the production effect.

    PubMed

    Ozubko, Jason D; Major, Jennifer; MacLeod, Colin M

    2014-01-01

    The production effect is the finding that words spoken aloud at study are subsequently remembered better than are words read silently at study. According to the distinctiveness account, aloud words are remembered better because the act of speaking those words aloud is encoded and later recovery of this information can be used to infer that those words were studied. An alternative account (the strength-based account) is that memory strength is simply greater for words read aloud. To discriminate these two accounts, we investigated study mode judgements (i.e., "aloud"/"silent"/"new" ratings): The strength-based account predicts that "aloud" responses should positively correlate with memory strength, whereas the distinctiveness account predicts that accuracy of study mode judgements will be independent of memory strength. Across three experiments, where the strength of some silent words was increased by repetition, study mode was discriminable regardless of strength-even when the strength of aloud and repeated silent items was equivalent. Consistent with the distinctiveness account, we conclude that memory for "aloudness" is independent of memory strength and a likely candidate to explain the production effect.

  15. The effect of life-history and mode of inheritance on neutral genetic variability.

    PubMed

    Charlesworth, B

    2001-04-01

    Formulae for the effective population sizes of autosomal, X-linked, Y-linked and maternally transmitted loci in age-structured populations are developed. The approximations used here predict both asymptotic rates of increase in probabilities of identity, and equilibrium levels of neutral nucleotide site diversity under the infinite-sites model. The applications of the results to the interpretation of data on DNA sequence variation in Drosophila, plant, and human populations are discussed. It is concluded that sex differences in demographic parameters such as adult mortality rates generally have small effects on the relative effective population sizes of loci with different modes of inheritance, whereas differences between the sexes in variance in reproductive success can have major effects, either increasing or reducing the effective population size for X-linked loci relative to autosomal or Y-linked loci. These effects need to be accounted for when trying to understand data on patterns of sequence variation for genes with different transmission modes.

  16. Dispersing artifacts in FT-STS: a comparison of set point effects across acquisition modes.

    PubMed

    Macdonald, A J; Tremblay-Johnston, Y-S; Grothe, S; Chi, S; Dosanjh, P; Johnston, S; Burke, S A

    2016-10-14

    Fourier-transform scanning tunnelling spectroscopy (FT-STS), or quasiparticle interference, has become an influential tool for the study of a wide range of important materials in condensed matter physics. However, FT-STS in complex materials is often challenging to interpret, requiring significant theoretical input in many cases, making it crucial to understand potential artifacts of the measurement. Here, we compare the most common modes of acquiring FT-STS data and show through both experiment and simulations that artifact features can arise that depend on how the tip height is stabilized throughout the course of the measurement. The most dramatic effect occurs when a series of dI/dV maps at different energies are acquired with simultaneous constant current feedback; here a feature that disperses in energy appears that is not observed in other measurement modes. Such artifact features are similar to those arising from real physical processes in the sample and are susceptible to misinterpretation. PMID:27607539

  17. Effect of wind tunnel acoustic modes on linear oscillating cascade aerodynamics

    NASA Technical Reports Server (NTRS)

    Buffum, Daniel H.; Fleeter, Sanford

    1993-01-01

    The aerodynamics of a biconvex airfoil cascade oscillating in torsion is investigated using the unsteady aerodynamic influence coefficient technique. For subsonic flow and reduced frequencies as large as 0.9, airfoil surface unsteady pressures resulting from oscillation of one of the airfoils are measured using flush-mounted high-frequency-response pressure transducers. The influence coefficient data are examined in detail and then used to predict the unsteady aerodynamics of a cascade oscillating at various interblade phase angles. These results are correlated with experimental data obtained in the traveling-wave mode of oscillation and linearized analysis predictions. It is found that the unsteady pressure disturbances created by an oscillating airfoil excite wind tunnel acoustic modes which have detrimental effects on the experimental data. Acoustic treatment is proposed to rectify this problem.

  18. Finite ballooning angle effects on ion temperature gradient driven mode in gyrokinetic flux tube simulations

    SciTech Connect

    Singh, Rameswar; Brunner, S.; Ganesh, R.; Jenko, F.

    2014-03-15

    This paper presents effects of finite ballooning angles on linear ion temperature gradient (ITG) driven mode and associated heat and momentum flux in Gyrokinetic flux tube simulation GENE. It is found that zero ballooning angle is not always the one at which the linear growth rate is maximum. The ITG mode acquires a short wavelength (SW) branch (k{sub ⊥}ρ{sub i} > 1) when growth rates maximized over all ballooning angles are considered. However, the SW branch disappears on reducing temperature gradient showing characteristics of zero ballooning angle SWITG in case of extremely high temperature gradient. Associated heat flux is even with respect to ballooning angle and maximizes at nonzero ballooning angle while the parallel momentum flux is odd with respect to the ballooning angle.

  19. The emotional male victim: effects of presentation mode on judged credibility.

    PubMed

    Landström, Sara; Ask, Karl; Sommar, Charlotte

    2015-02-01

    The emotional victim effect (EVE, i.e., that the emotionality of a victim's demeanor affects perceived credibility) is a robust research finding for female victims of rape but much less explored for other types of victims and crimes. In this article, we investigate the EVE with a male assault complainant. In addition, we vary the presentation mode via which the complainant is shown to the assessors. A sample of law students (N = 81) participated in an experiment where they viewed and assessed credibility of a male complainant who appeared either live or on video. The complainant behaved either in an emotional or a neutral manner. Result showed that the presentation mode but not the EVE affected the assessors' credibility assessments: The complainant was perceived as more truthful when communicating live, as opposed to via video. Practical implications, as well as the generality of the EVE, are discussed.

  20. Effective dipole moment for the mode coupling instability: Mapping of self-consistent wake models

    SciTech Connect

    Roecker, T. B.; Zhdanov, S. K.; Ivlev, A. V.; Morfill, G. E.; Lampe, M.; Joyce, G.

    2012-07-15

    The theory of the mode coupling instability operating in two-dimensional plasma crystals is generalized, by employing the linear plasma response formalism to describe the interparticle interactions self-consistently. In this approach, the underlying ion distribution function is calculated from first principles. Subthermal and suprathermal regimes of the ion flow are considered. A mapping procedure is proposed, which relates the self-consistent coupling coefficients to the effective dipole moment of the wake-the parameter which characterizes the mode coupling in the framework of the conventionally used Yukawa/point-wake model. The importance of the self-consistent approach is demonstrated by comparing the theoretically obtained dipole moments with the values deduced from experiments.

  1. Enhanced magnetoelectric effect in longitudinal-longitudinal mode laminate with cofired interdigitated electrodes

    NASA Astrophysics Data System (ADS)

    Yan, Yongke; Zhou, Yuan; Priya, Shashank

    2014-01-01

    In this letter, we describe a low-temperature cofiring technique to embed the interdigitated electrodes (IDE) inside the piezoelectric ceramic layer to achieve longitudinally (L) poled magnetoelectric (ME) laminates. The ME voltage coefficient of this L-L mode composite was found to be 4.41 V cm-1 Oe-1 at 1 kHz, which is 340% higher than that of L-T (transversal) mode. IDE based longitudinal poling and piezoelectric response was evaluated by impedance changes and piezoresponse force microscopy, illustrating the effect of inactive/ineffective zone in the range beneath and above the fingers with vanishing fields. At an electric field of 50 V/cm, the composite was found to generate magnetic field on the order of 175 μG at 1 kHz.

  2. Effects of bandwidth-limiting tuning elements in synchronously pumped mode-locked lasers

    SciTech Connect

    Zandi, B.; Casperson, L.W.; MacFarlane, D.L. )

    1990-03-01

    A description of bandwidth-limiting tuning filters is introduced into a semiclassical model for synchronously pumped mode-locked dye lasers. The finite phase memory of the molecular wave functions is included as are the isotropic molecular distribution and the finite vibrational relaxation times. The new set of equations has been solved numerically using the best available values for the various parameters. The results have been compared with experimental data obtained using a rhodamine 6G dye laser, which is synchronously pumped using an acousto-optically mode-locked argon laser. Tuning element effects have been studied using two- and three-plate birefringent filters and a tuning wedge, and the experimental results agree with the numerical solutions.

  3. Effect of set size, age, and mode of stimulus presentation on information-processing speed.

    NASA Technical Reports Server (NTRS)

    Norton, J. C.

    1972-01-01

    First, second, and third grade pupils served as subjects in an experiment designed to show the effect of age, mode of stimulus presentation, and information value on recognition time. Stimuli were presented in picture and printed word form and in groups of 2, 4, and 8. The results of the study indicate that first graders are slower than second and third graders who are nearly equal. There is a gross shift in reaction time as a function of mode of stimulus presentation with increase in age. The first graders take much longer to identify words than pictures, while the reverse is true of the older groups. With regard to set size, a slope appears in the pictures condition in the older groups, while for first graders, a large slope occurs in the words condition and only a much smaller one for pictures.

  4. Arc-discharge effects on residual stress and refractive index in single-mode optical fibers.

    PubMed

    Wang, Pengfei; Jenkins, Micah H; Gaylord, Thomas K

    2016-03-20

    Arc-discharge effects on the residual stress and refractive index in single-mode optical fibers are investigated using a previously developed three-dimensional concurrent stress-index measurement method. Using commercial optical fibers and a commercial fusion splicer, the residual stress and refractive index perturbations caused by weak electrical arc discharges in single-mode fibers were measured. Refractive index changes greater than 10-4 and longitudinal perturbation lengths of less than 500 μm were shown to be possible. The subsequent prospects for arc-induced long-period fiber gratings are analyzed, and a typical transmission resonance is predicted to have a depth of 56 dB and a bandwidth of 0.08 nm at a wavelength of 1585 nm. The results of this investigation will be useful in modeling device performance and optimization of arc-induced long-period fiber grating fabrication.

  5. Dispersing artifacts in FT-STS: a comparison of set point effects across acquisition modes

    NASA Astrophysics Data System (ADS)

    Macdonald, A. J.; Tremblay-Johnston, Y.-S.; Grothe, S.; Chi, S.; Dosanjh, P.; Johnston, S.; Burke, S. A.

    2016-10-01

    Fourier-transform scanning tunnelling spectroscopy (FT-STS), or quasiparticle interference, has become an influential tool for the study of a wide range of important materials in condensed matter physics. However, FT-STS in complex materials is often challenging to interpret, requiring significant theoretical input in many cases, making it crucial to understand potential artifacts of the measurement. Here, we compare the most common modes of acquiring FT-STS data and show through both experiment and simulations that artifact features can arise that depend on how the tip height is stabilized throughout the course of the measurement. The most dramatic effect occurs when a series of dI/dV maps at different energies are acquired with simultaneous constant current feedback; here a feature that disperses in energy appears that is not observed in other measurement modes. Such artifact features are similar to those arising from real physical processes in the sample and are susceptible to misinterpretation.

  6. Wall thickness effect on the resistive wall mode stability in toroidal plasmas

    SciTech Connect

    Zheng, L.-J.; Kotschenreuther, M.T.

    2005-07-15

    The effect of finite wall thickness on the stability of n=1 resistive wall modes in toroidal plasmas is investigated. A fusion reactor-relevant configuration is examined. The investigation employs a novel ideal-magnetohydrodynamics adaptive shooting code for axisymmetric plasmas, extended to take into account the wall thickness. Although finite wall thickness generally reduces the growth rate of the resistive wall modes, no contribution to stabilization is found to be made by the portion of the wall that is located beyond the critical position for perfectly conducting wall stabilization. Thus, when the inner side of the wall lies near the critical wall position, the scaling of the growth rate versus wall thickness in the realistic thick-wall calculation is significantly different from that of the usual thin-wall theory. The thin-wall estimate is relevant only when the wall is brought very close to the plasma and is not too thick.

  7. Using Failure Mode and Effects Analysis to design a comfortable automotive driver seat.

    PubMed

    Kolich, Mike

    2014-07-01

    Given enough time and use, all designs will fail. There are no fail-free designs. This is especially true when it comes to automotive seating comfort where the characteristics and preferences of individual customers are many and varied. To address this problem, individuals charged with automotive seating comfort development have, traditionally, relied on iterative and, as a result, expensive build-test cycles. Cost pressures being placed on today's vehicle manufacturers have necessitated the search for more efficient alternatives. This contribution aims to fill this need by proposing the application of an analytical technique common to engineering circles (but new to seating comfort development), namely Design Failure Mode and Effects Analysis (DFMEA). An example is offered to describe how development teams can use this systematic and disciplined approach to highlight potential seating comfort failure modes, reduce their risk, and bring capable designs to life.

  8. Effect of heating mode on sinterability of Fe-Ni steels.

    PubMed

    Annamalai, A Raja; Kumar, Rajiv; Upadhyaya, Anish; Agrawal, Dinesh

    2011-01-01

    The present study examines the effect of heating mode on the densification, microstructure, and mechanical properties of iron-nickel steel with graphite and phosphorus addition. The compacts were sintered in conventional (radiatively-heated) and microwave (2.45 GHz, multimode) furnaces at 1120 degrees C for 1 hour in forming gas (dissociated ammonia atmosphere, 95% N2-5% H2). The experimental results show that microwave sintered alloy has better properties compared with the conventionally sintered counterparts. Detailed analyses by using optical microscopy and scanning electron microscopy (SEM) reveal that microwave sintered sample has finer microstructure. SEM examination of the fractured surfaces indicate that a mixed mode fracture containing both, ductile and brittle types, is present in microwave sintered alloy, in contrast with the brittle fracture only in conventional sintered counterpart.

  9. Dispersing artifacts in FT-STS: a comparison of set point effects across acquisition modes.

    PubMed

    Macdonald, A J; Tremblay-Johnston, Y-S; Grothe, S; Chi, S; Dosanjh, P; Johnston, S; Burke, S A

    2016-10-14

    Fourier-transform scanning tunnelling spectroscopy (FT-STS), or quasiparticle interference, has become an influential tool for the study of a wide range of important materials in condensed matter physics. However, FT-STS in complex materials is often challenging to interpret, requiring significant theoretical input in many cases, making it crucial to understand potential artifacts of the measurement. Here, we compare the most common modes of acquiring FT-STS data and show through both experiment and simulations that artifact features can arise that depend on how the tip height is stabilized throughout the course of the measurement. The most dramatic effect occurs when a series of dI/dV maps at different energies are acquired with simultaneous constant current feedback; here a feature that disperses in energy appears that is not observed in other measurement modes. Such artifact features are similar to those arising from real physical processes in the sample and are susceptible to misinterpretation.

  10. The effect of types I and III interferons on adrenocortical cells and its possible implications for autoimmune Addison's disease.

    PubMed

    Hellesen, A; Edvardsen, K; Breivik, L; Husebye, E S; Bratland, E

    2014-06-01

    Autoimmune Addison's disease (AAD) is caused by selective destruction of the hormone-producing cells of the adrenal cortex. As yet, little is known about the potential role played by environmental factors in this process. Type I and/or type III interferons (IFNs) are signature responses to virus infections, and have also been implicated in the pathogenesis of autoimmune endocrine disorders such as type 1 diabetes and autoimmune thyroiditis. Transient development of AAD and exacerbation of established or subclinical disease, as well as the induction of autoantibodies associated with AAD, have been reported following therapeutic administration of type I IFNs. We therefore hypothesize that exposure to such IFNs could render the adrenal cortex susceptible to autoimmune attack in genetically predisposed individuals. In this study, we investigated possible immunopathological effects of type I and type III IFNs on adrenocortical cells in relation to AAD. Both types I and III IFNs exerted significant cytotoxicity on NCI-H295R adrenocortical carcinoma cells and potentiated IFN-γ- and polyinosine-polycytidylic acid [poly (I : C)]-induced chemokine secretion. Furthermore, we observed increased expression of human leucocyte antigen (HLA) class I molecules and up-regulation of 21-hydroxylase, the primary antigenic target in AAD. We propose that these combined effects could serve to initiate or aggravate an ongoing autoimmune response against the adrenal cortex in AAD.

  11. Effects of gelatin sponge combined with moist wound-healing nursing intervention in the treatment of phase III bedsore

    PubMed Central

    LI, YANLING; YAO, MEIYING; WANG, XIA; ZHAO, YANQING

    2016-01-01

    Pressure sore pertains to tissue damage or necrosis that occurs due to lack of adequate nutrition following long-term exposure to pressure and decreased blood circulation. The aim of the study was to examine the effects of gelatin sponge combined with moist wound-healing nursing intervention in the treatment of phase III bedsore. In total, 50 patients with phase III bedsore were included in the present study. The patients were randomly divided into the control (n=25) and observation (n=25) groups. Patients in the control group received conventional nursing, while those in the observation group received gelatin sponge combined with moist wound healing nursing. The effects of the two nursing methods were compared and analyzed. The results showed that the improvement rate of the observation group was significantly higher than that of the control group (P<0.05). The Branden score and area of pressure sore of the observation group were significantly lower than those of the control group (P<0.05). The frequency and time of dressing change and the average cost of hospitalization of the observation group were significantly lower than those of the control group (P<0.001). In conclusion, gelatin sponge combined with moist wound-healing nursing intervention may significantly improve the treatment of phase III bedsore. PMID:27313666

  12. Proteomic and metabolomic analysis on the toxicological effects of As (III) and As (V) in juvenile mussel Mytilus galloprovincialis.

    PubMed

    Yu, Deliang; Ji, Chenglong; Zhao, Jianmin; Wu, Huifeng

    2016-05-01

    Inorganic arsenic (As) is a known pollutant including two chemical forms (arsenite (As III) and arsenate (As V)), in marine and coastal environment. Marine mussel Mytilus galloprovincialis is an important environmental monitoring species around the world. In this study, we focused on valence-specific responses of As in juvenile mussel M. galloprovincialis using a combined proteomic and metabolomic approach. Metabolic responses indicated that As (III) mainly caused disturbance in osmotic regulation in juvenile mussels. As (V) caused disturbances in both osmotic regulation and energy metabolism marked by different metabolic responses, including betaine, taurine, glucose and glycogen. Proteomic responses exhibited that As (III) had a significant negative effect on cytoskeleton and cell structure (actin and collagen alpha-6(VI) chain). As (V) affected some key enzymes involved in energy metabolism (cytosolic malate dehydrogenase, cMDH) and cell development (ornithine aminotransferase and astacin). Overall, all these results confirmed the valence-specific responses in juvenile mussels to As exposures. These findings demonstrate that a combined metabolomic and proteomic approach could provide an important insight into the toxicological effects of environmental pollutants in organisms.

  13. DRD4-exonIII-VNTR moderates the effect of childhood adversities on emotional resilience in young-adults.

    PubMed

    Das, Debjani; Cherbuin, Nicolas; Tan, Xiaoyun; Anstey, Kaarin J; Easteal, Simon

    2011-01-01

    Most individuals successfully maintain psychological well-being even when exposed to trauma or adversity. Emotional resilience or the ability to thrive in the face of adversity is determined by complex interactions between genetic makeup, previous exposure to stress, personality, coping style, availability of social support, etc. Recent studies have demonstrated that childhood trauma diminishes resilience in adults and affects mental health. The Dopamine receptor D4 (DRD4) exon III variable number tandem repeat (VNTR) polymorphism was reported to moderate the impact of adverse childhood environment on behaviour, mood and other health-related outcomes. In this study we investigated whether DRD4-exIII-VNTR genotype moderates the effect of childhood adversities (CA) on resilience. In a representative population sample (n = 1148) aged 30-34 years, we observed an interactive effect of DRD4 genotype and CA (β = 0.132; p = 0.003) on resilience despite no main effect of the genotype when effects of age, gender and education were controlled for. The 7-repeat allele appears to protect against the adverse effect of CA since the decline in resilience associated with increased adversity was evident only in individuals without the 7-repeat allele. Resilience was also significantly associated with approach-/avoidance-related personality measures (behavioural inhibition/activation system; BIS/BAS) measures and an interactive effect of DRD4-exIII-VNTR genotype and CA on BAS was observed. Hence it is possible that approach-related personality traits could be mediating the effect of the DRD4 gene and childhood environment interaction on resilience such that when stressors are present, the 7-repeat allele influences the development of personality in a way that provides protection against adverse outcomes.

  14. Absorption effects on the Mie plasmon-polariton modes in two-dimensional plasmonic photonic crystals

    NASA Astrophysics Data System (ADS)

    Diaz-Valencia, B. F.; Mejía-Salazar, J. R.; Porras-Montenegro, N.

    2015-09-01

    We have theoretically investigated the absorption effects on the Mie plasmonic resonances in single metallic shell rods and two-dimensional plasmonic photonic crystals. Present results show that Mie resonances stemming from the dipolar and quadrupolar contributions are robust to absorption effects not only in single scatterers but also in the case of two-dimensional plasmonic photonic crystals. On the other hand, we have found that the extinction (Qext) and scattering (Qsca) efficiencies corresponding to an isolated metallic rod may be employed to predict the frequency range for flat or slow dispersive photonic bands in plasmonic photonic crystals, indicating a robust behavior of such resonant modes.

  15. Effective second-order susceptibility in photonic crystals mode of centrosymmetric materials

    NASA Astrophysics Data System (ADS)

    Feigel, A.; Kotler, Z.; Sfez, B.

    2002-02-01

    A technique for obtaining efficient bulk second-order susceptibility in noncentrosymmetric photonic crystals (PC) made of centrosymmetric materials is discussed. The effect is based on the electric quadrupole effect, strong electromagnetic mode deformation, and nonhomogeneous contribution to volume polarization from different parts of the PC. The required symmetry breaking is introduced on the macroscale of the PC unit cell. The obtained structural χ(2)str is comparable with the second-order susceptibility of ordinary nonlinear materials. Phase matching can be achieved by introducing symmetry modulation (quasi-phase-matching) during fabrication of the PC.

  16. Global fine-mode aerosol radiative effect, as constrained by comprehensive observations

    NASA Astrophysics Data System (ADS)

    Chung, Chul E.; Chu, Jung-Eun; Lee, Yunha; van Noije, Twan; Jeoung, Hwayoung; Ha, Kyung-Ja; Marks, Marguerite

    2016-07-01

    Aerosols directly affect the radiative balance of the Earth through the absorption and scattering of solar radiation. Although the contributions of absorption (heating) and scattering (cooling) of sunlight have proved difficult to quantify, the consensus is that anthropogenic aerosols cool the climate, partially offsetting the warming by rising greenhouse gas concentrations. Recent estimates of global direct anthropogenic aerosol radiative forcing (i.e., global radiative forcing due to aerosol-radiation interactions) are -0.35 ± 0.5 W m-2, and these estimates depend heavily on aerosol simulation. Here, we integrate a comprehensive suite of satellite and ground-based observations to constrain total aerosol optical depth (AOD), its fine-mode fraction, the vertical distribution of aerosols and clouds, and the collocation of clouds and overlying aerosols. We find that the direct fine-mode aerosol radiative effect is -0.46 W m-2 (-0.54 to -0.39 W m-2). Fine-mode aerosols include sea salt and dust aerosols, and we find that these natural aerosols result in a very large cooling (-0.44 to -0.26 W m-2) when constrained by observations. When the contribution of these natural aerosols is subtracted from the fine-mode radiative effect, the net becomes -0.11 (-0.28 to +0.05) W m-2. This net arises from total (natural + anthropogenic) carbonaceous, sulfate and nitrate aerosols, which suggests that global direct anthropogenic aerosol radiative forcing is less negative than -0.35 W m-2.

  17. Effects of sodium hypochlorite exposure mode on PES/PVP ultrafiltration membrane degradation.

    PubMed

    Causserand, Christel; Pellegrin, Bastien; Rouch, Jean-Christophe

    2015-11-15

    Drinking water production plants using membrane filtration processes report membrane failure issues. According to the literature, membrane degradation is often induced by exposure to sodium hypochlorite, an oxidant widely used during in-place cleanings. The present study focused on quantifying the effect of membrane exposure mode to hypochlorite on properties modifications of a PES/PVP ultrafiltration membrane widely used for drinking water production. For this purpose effects of sodium hypochlorite concentration, contact duration and exposure mode (static or dynamic) were investigated. The pH of the hypochlorite solution was set to 8 as it was demonstrated in numerous previous works that the pH range 7-8 leads to the most severe modification in the membrane characteristics. Membrane degradation was monitored at molecular scale by attenuated total reflectance infrared spectroscopy and at macroscopic scale by pure water permeability and elongation at break measurements. The results obtained in static (soaking) and dynamic (filtration and filtration/backwashing cycles) hypochlorite exposure modes indicated that PES/PVP membrane degradation progress was predominantly governed by hypochlorite oxidation rate. In the tested conditions, mechanical stress (pressure differentials) did not significantly contribute to membrane ageing. The correlation between molecular and macroscopic characterizations demonstrated that PVP degradation is responsible for the membrane integrity loss. A linear relationship between the loss of ductility of the membrane and the progress of the PVP degradation was obtained whatever the exposure mode. Thanks to experiments conducted at various hypochlorite concentrations and exposure durations, the hypochlorite dose parameter (hypochlorite concentration times contact time), widely used in the literature, was demonstrated to be inappropriate to describe the degradation rate: the hypochlorite concentration impact was shown to be dominating the

  18. Changes in convective properties over the solar cycle: effect on p-mode damping rates

    NASA Astrophysics Data System (ADS)

    Houdek, G.; Chaplin, W. J.; Appourchaux, T.; Christensen-Dalsgaard, J.; Däppen, W.; Elsworth, Y.; Gough, D. O.; Isaak, G. R.; New, R.; Rabello-Soares, M. C.

    2001-10-01

    Measurements of both solar irradiance and p-mode oscillation frequencies indicate that the structure of the Sun changes with the solar cycle. Balmforth, Gough & Merryfield investigated the effect of symmetrical thermal disturbances on the solar structure and the resulting pulsation frequency changes. They concluded that thermal perturbations alone cannot account for the variations in both irradiance and p-mode frequencies, and that the presence of a magnetic field affecting acoustical propagation is the most likely explanation of the frequency change, in the manner suggested earlier by Gough & Thompson and by Goldreich et al. Numerical simulations of Boussinesq convection in a magnetic field have shown that at high Rayleigh number the magnetic field can modify the preferred horizontal length scale of the convective flow. Here, we investigate the effect of changing the horizontal length scale of convective eddies on the linewidths of the acoustic resonant mode peaks observed in helioseismic power spectra. The turbulent fluxes in these model computations are obtained from a time-dependent, non-local generalization of the mixing-length formalism. The modelled variations are compared with p-mode linewidth changes revealed by the analysis of helioseismic data collected by the Birmingham Solar-Oscillations Network (BiSON); these low-degree (low-l) observations cover the complete falling phase of solar activity cycle 22. The results are also discussed in the light of observations of solar-cycle variations of the horizontal size of granules and with results from 2D simulations by Steffen of convective granules.

  19. Modes of reproduction and the accumulation of deleterious mutations with multiplicative fitness effects.

    PubMed Central

    Haccou, Patsy; Schneider, Maria Victoria

    2004-01-01

    Mutational load depends not only on the number and nature of mutations but also on the reproductive mode. Traditionally, only a few specific reproductive modes are considered in the search of explanations for the maintenance of sex. There are, however, many alternatives. Including these may give radically different conclusions. The theory on deterministic deleterious mutations states that in large populations segregation and recombination may lead to a lower load of deleterious mutations, provided that there are synergistic interactions. Empirical research suggests that effects of deleterious mutations are often multiplicative. Such situations have largely been ignored in the literature, since recombination and segregation have no effect on mutation load in the absence of epistasis. However, this is true only when clonal reproduction and sexual reproduction with equal male and female ploidy are considered. We consider several alternative reproductive modes that are all known to occur in insects: arrhenotoky, paternal genome elimination, apomictic thelytoky, and automictic thelytoky with different cytological mechanisms to restore diploidy. We give a method that is based on probability-generating functions, which provides analytical and numerical results on the distributions of deleterious mutations. Using this, we show that segregation and recombination do make a difference. Furthermore, we prove that a modified form of Haldane's principle holds more generally for thelytokous reproduction. We discuss the implications of our results for evolutionary transitions between different reproductive modes in insects. Since the strength of Muller's ratchet is reduced considerably for several forms of automictic thelytoky, many of our results are expected to be also valid for initially small populations. PMID:15020489

  20. Investigation on the co-luminescence effect of europium (III)-lanthanum(III)-dopamine-sodium dodecylbenzene sulfonate system and its application.

    PubMed

    Si, Hailin; Zhao, Fang; Cai, Huan

    2013-01-01

    A novel luminescence, enhancement phenomenon in the europium(III)-dopamine-sodium dodecylbenzene sulfonate system was observed when lanthanum(III) was added. Based on this, a sensitive co-luminescence method was established for the determination of dopamine. The luminescence signal for the europium (III)-lanthanum(III)-dopamine-sodium dodecylbenzene sulfonate system was monitored at λ(ex) = 300 nm, λ(em) = 618 nm and pH 8.3. Under optimized conditions, the enhanced luminescence signal responded linearly to the concentration of dopamine in the range 1.0 × 10(-10)-5.0 × 10(-7) mol/L with a correlation coefficient of 0.9993 (n = 11). The detection limit (3σ) was 2.7 × 10(-11) mol/L and the relative standard deviation for 11 parallel measurements of 3.0 × 10(-8) mol/L dopamine was 1.9%. The presented method was successfully applied for the estimation of dopamine in samples of pharmaceutical preparations, human serum and urine. The possible luminescence enhancement mechanism of the system is discussed briefly.

  1. [Effect of extraoral facemask appliance in 48 cases of malocclusion and dentofacial deformity in class III].

    PubMed

    Zhang, X; Su, X

    1993-10-01

    Malocclusion and dentofacial deformity in class III is always characterized by maxillary skeletal retrusion and/or mandibular protrusion. It affects function and facial esthetics. An orthopedic mask appliance with class III extraoral traction made by the authors was applied in 48 cases from Aug. 1985 to Oct. 1991. The study population included 5 patients with deciduous dentition, 30 with permanent dentition, and 13 with mixed dentition. The second deciduous molars or permanent first molars are a class III relationship. These exhibited bilateral crossbites and negative overjet greater than 5 mm severe arch length discrepancies existed in both arches, maxillary skeletal retrusion and/or mandibular protrusion. The results of these 48 cases were very satisfactory. The relationship between maxillary and mandibular second deciduous molar or permanent first molar all showed centric occlusal position. Dentofacial orthopedics therapy is one of the most important treatments of malocclusion and dentofacial deformity. The choice of therapy and orthodontic force must follow the age and endurance of the patient. Also, exercise of the tongue muscle must be considered.

  2. Effect of annealing time of an ice crystal on the activity of type III antifreeze protein.

    PubMed

    Takamichi, Manabu; Nishimiya, Yoshiyuki; Miura, Ai; Tsuda, Sakae

    2007-12-01

    Antifreeze proteins (AFPs) possess a unique ability to bind to a seed ice crystal to inhibit its growth. The strength of this binding has been evaluated by thermal hysteresis (TH). In this study, we examined the dependence of TH on experimental parameters, including cooling rate, annealing time, annealing temperature and the size of the seed ice crystal for an isoform of type III AFP from notched-fin eelpout (nfeAFP8). TH of nfeAFP8 dramatically decreased when using a fast cooling rate (0.20 degrees C x min(-1)). It also decreased with increasing seed crystal size under a slow cooling rate (0.01 degrees C x min(-1)), but such dependence was not detected under the fast cooling rate. TH was enhanced 1.4- and 2.5-fold when ice crystals were annealed for 3 h at 0.05 and 0.25 degrees C below T(m), respectively. After annealing for 2 h at 0.25 degrees C below T(m), TH activity showed marked dependence on the size of ice crystals. These results suggest that annealing of an ice crystal for 2-3 h significantly increased the TH value of type III AFP. Based on a proposed adsorption-inhibition model, we assume that type III AFP undergoes additional ice binding to the convex ice front over a 2-3 h time scale, which results in the TH dependence on the annealing time.

  3. Effect of the drift wave turbulence on the evolution of the low-[ital m] tearing modes

    SciTech Connect

    Siva Rama Prasad, P.V.; Tewari, D.P. )

    1994-01-01

    The effect of the background drift wave turbulence on the evolution of the low-[ital m] tearing modes has been studied, in the quasilinear regime, in various limiting cases. It is found, in the cases of the [ital m]=1 classical, collisionless, and drift-tearing modes, that the turbulence introduces finite real frequencies to these modes, which are otherwise purely growing ones, but reduces their instability activity. In the case of the [ital m][ge]2 classical modes, in a limit [vert bar][alpha][vert bar][sup 1/2][much gt][rho][sub [ital i

  4. Finite Larmor radius effects on the (m = 2, n = 1) cylindrical tearing mode

    SciTech Connect

    Chen, Y.; Chowdhury, J.; Parker, S. E.; Wan, W.

    2015-04-15

    New field solvers are developed in the gyrokinetic code GEM [Chen and Parker, J. Comput. Phys. 220, 839 (2007)] to simulate low-n modes. A novel discretization is developed for the ion polarization term in the gyrokinetic vorticity equation. An eigenmode analysis with finite Larmor radius effects is developed to study the linear resistive tearing mode. The mode growth rate is shown to scale with resistivity as γ ∼ η{sup 1∕3}, the same as the semi-collisional regime in previous kinetic treatments [Drake and Lee, Phys. Fluids 20, 1341 (1977)]. Tearing mode simulations with gyrokinetic ions are verified with the eigenmode calculation.

  5. Characterisation of effective mode-field diameter of coupled multi-core fibre

    NASA Astrophysics Data System (ADS)

    Nakajima, K.; Saito, K.; Goto, Y.; Fukai, C.; Kurashima, T.

    2014-05-01

    We experimentally investigate the effective mode-field diameter (MFD) of coupled type multi-core fibres (MCFs). Effective MFDs of two different coupled MCFs are derived by considering the relationship with the splice loss characteristics. We also examine the applicability of conventional variable aperture (VA) and far-field pattern (FFP) scanning methods by considering the consistency with the effective MFD values. Our results show the potential of the VA method for evaluating the effective MFD characteristics of a coupled type MCF with arbitral field distribution. We also show that the effective MFD can be estimated by considering the widest and narrowest MFD values even if the field distribution becomes a crosswise. These results are useful when we examine the detail characteristics of a coupled type MCF as both transmission and/or sensing medium.

  6. Phonon and free-charge carrier properties in group-III nitride heterostructures investigated by spectroscopic ellipsometry and optical Hall effect

    NASA Astrophysics Data System (ADS)

    Schoeche, Stefan

    The material class of group-III nitrides gained tremendous technological importance for optoelectronic and high-power/high-frequency amplification devices. Tunability of the direct band gap from 0.65 eV (InN) to 6.2 eV (AlN) by alloying, high breakthrough voltages and intrinsic mobilities, as well as the formation of highly mobile 2d electron gases (2DEG) at heterointerfaces make these compounds ideal for many applications. GaN and Ga-rich alloys are well studied and current research is mainly device-oriented. For example, choice and quality of the gate dielectric significantly influence device performance in high-electron mobility transistors (HEMT) which utilize highly mobile 2DEGs at heterointerfaces. Experimental access to the 2DEG channel properties without influence from parasitic currents or contact properties are desirable. In- and Al-rich ternary alloys are less explored than Ga-rich compounds. For InN and In-rich alloys, while many material parameters such as stiffness constants or effective mass values are largely unknown, reliable p-type doping is a major challenge, also because p-type conducting channels are buried within highly conductive n-type material formed at the surface and interfaces preventing electrical characterization. For AlN and high-Al content alloys, doping mechanisms are not understood and reliable fabrication of material with high free-charge carrier (FCC) concentrations was achieved just recently. Difficulties to form ohmic contacts impair electrical measurements and optical characterization is impeded by lack of high-energy excitation sources. In this work, spectroscopic ellipsometry over the wide spectral range from the THz to VUV in combination with optical Hall effect (generalized ellipsometry with applied magnetic field) from THz to MIR are applied in order to investigate the phonon modes and FCC properties in group-III nitride heterostructures. Adequate model descriptions and analysis strategies are introduced which allow

  7. Soft-collinear mode for jet cross sections in soft collinear effective theory

    NASA Astrophysics Data System (ADS)

    Chien, Yang-Ting; Hornig, Andrew; Lee, Christopher

    2016-01-01

    We propose the addition of a new "soft-collinear" mode to soft collinear effective theory (SCET) below the usual soft scale to factorize and resum logarithms of jet radii R in jet cross sections. We consider exclusive 2-jet cross sections in e+e- collisions with an energy veto Λ on additional jets. The key observation is that there are actually two pairs of energy scales whose ratio is R : the transverse momentum Q R of the energetic particles inside jets and their total energy Q , and the transverse momentum Λ R of soft particles that are cut out of the jet cones and their energy Λ . The soft-collinear mode is necessary to factorize and resum logarithms of the latter hierarchy. We show how this factorization occurs in the jet thrust cross section for cone and kT -type algorithms at O (αs) and using the thrust cone algorithm at O (αs2) . We identify the presence of hard-collinear, in-jet soft, global (veto) soft, and soft-collinear modes in the jet thrust cross section. We also observe here that the in-jet soft modes measured with thrust are actually the "csoft" modes of the theory SCET+ . We dub the new theory with both csoft and soft-collinear modes "SCET++ ." We go on to explain the relation between the "unmeasured" jet function appearing in total exclusive jet cross sections and the hard-collinear and csoft functions in measured jet thrust cross sections. We do not resum logs that are nonglobal in origin, arising from the ratio of the scales of soft radiation whose thrust is measured at Q τ /R and of the soft-collinear radiation at 2 Λ R . Their resummation would require the introduction of additional operators beyond those we consider here. The steps we outline here are a necessary part of summing logs of R that are global in nature and have not been factorized and resummed beyond leading-log level previously.

  8. Incremental Criterion Validity of the WJ-III COG Clinical Clusters: Marginal Predictive Effects beyond the General Factor

    ERIC Educational Resources Information Center

    McGill, Ryan J.

    2015-01-01

    The current study examined the incremental validity of the clinical clusters from the Woodcock-Johnson III Tests of Cognitive Abilities (WJ-III COG) for predicting scores on the Woodcock-Johnson III Tests of Achievement (WJ-III ACH). All participants were children and adolescents (N = 4,722) drawn from the nationally representative WJ-III…

  9. Self-recovery effect of orbital angular momentum mode of circular beam in weak non-Kolmogorov turbulence.

    PubMed

    Zhang, Tao; Liu, Yi-Dong; Wang, Jiandong; Liu, Pusheng; Yang, Yuanjie

    2016-09-01

    It is generally true that the orbital angular momentum (OAM) mode persistently degenerate when a vortex beam propagates in the atmospheric turbulence. Here, however, we unveil an interesting self-recovery effect of OAM mode of the circular beam (CiB) in weak non-Kolmogorov turbulence. We show that the CiB displays the self-focusing effect and has clear focus in the weak non-Kolmogorov turbulence if we choose proper complex parameters, and the detection probability of the original OAM mode reaches the maximum at the focus. Our study proposes a method to alleviate the turbulent effects on OAM-based communication. PMID:27607655

  10. Self-recovery effect of orbital angular momentum mode of circular beam in weak non-Kolmogorov turbulence.

    PubMed

    Zhang, Tao; Liu, Yi-Dong; Wang, Jiandong; Liu, Pusheng; Yang, Yuanjie

    2016-09-01

    It is generally true that the orbital angular momentum (OAM) mode persistently degenerate when a vortex beam propagates in the atmospheric turbulence. Here, however, we unveil an interesting self-recovery effect of OAM mode of the circular beam (CiB) in weak non-Kolmogorov turbulence. We show that the CiB displays the self-focusing effect and has clear focus in the weak non-Kolmogorov turbulence if we choose proper complex parameters, and the detection probability of the original OAM mode reaches the maximum at the focus. Our study proposes a method to alleviate the turbulent effects on OAM-based communication.

  11. Solvent friction effects propagate over the entire protein molecule through low-frequency collective modes.

    PubMed

    Moritsugu, Kei; Kidera, Akinori; Smith, Jeremy C

    2014-07-24

    Protein solvation dynamics has been investigated using atom-dependent Langevin friction coefficients derived directly from molecular dynamics (MD) simulations. To determine the effect of solvation on the atomic friction coefficients, solution and vacuum MD simulations were performed for lysozyme and staphylococcal nuclease and analyzed by Langevin mode analysis. The coefficients thus derived are roughly correlated with the atomic solvent-accessible surface area (ASA), as expected from the fact that friction occurs as the result of collisions with solvent molecules. However, a considerable number of atoms with higher friction coefficients are found inside the core region. Hence, the influence of solvent friction propagates into the protein core. The internal coefficients have large contributions from the low-frequency modes, yielding a simple picture of the surface-to-core long-range damping via solvation governed by collective low-frequency modes. To make use of these findings in implicit-solvent modeling, we compare the all-atom friction results with those obtained using Langevin dynamics (LD) with two empirical representations: the constant-friction and the ASA-dependent (Pastor-Karplus) friction models. The constant-friction model overestimates the core and underestimates the surface damping whereas the ASA-dependent friction model, which damps protein atoms only on the solvent-accessible surface, reproduces well the friction coefficients for both the surface and core regions observed in the explicit-solvent MD simulations. Therefore, in LD simulation, the solvent friction coefficients should be imposed only on the protein surface. PMID:24999844

  12. [Effect of afforestation modes on soil microbial community and nitrogen functional genes in Hippophae rhamnoides plantation].

    PubMed

    Yang, Dan; Yu, Xuan; Liu, Xu; Liu, Jin-liana; Zhang, Shun-xiang; Yu, Ze-qun

    2015-12-01

    The study aimed to assess the effect of different afforestation modes on microbial composition and nitrogen functional genes in soil. Soil samples from a pure Hippophae rhamnoides stand (SS) and three mixed stands, namely, H. rhamnoides and Pinus tabuliformis (SY), H. rhamnoides and Platycladus orientalis (SB), H. rhamnoides and Robinia pseucdoacacia (SC) were selected. The results showed that the total PLFA (TPLFA), bacterial PLFA, gram positive bacterial PLFA (G⁺PLFA) were significantly higher in soil samples from other three stands than those of the pure one. However, no significant difference was found for fungal PLFA among them. The abundance of nifH, amoA, nirK and narG genes were higher in SY and SC than in SS. The TPLFA, G⁺PLFA, gram negative bacterial PLFA (G⁻PLFA), and all of the detected gene abundance were significantly and positively correlated with soil pH, total organic carbon, total nitrogen, ammonium nitrogen and available potassium. Afforestation modes affected indirectly soil microbial composition and functional genes through soil properties. Mixing P. tabuliformis or P. orientalis with H. rhamnoides might be suitable afforestation modes, which might improve soil quality. PMID:27111999

  13. Thick-wall effects in the theory of resistive wall modes

    SciTech Connect

    Pustovitov, V. D.

    2012-06-15

    Magnetic interaction of the plasma perturbations with the nearby resistive wall is considered as a resistive wall mode (RWM) problem, but with two essential differences from the traditional thin-wall approach. First, the wall is treated as magnetically thick, which means that the skin depth is not assumed larger than the wall thickness. Second, the plasma is allowed to enter the region where the RWM must be deeply unstable without rotation. The latter corresponds to the plasma operation above the no-wall stability limit demonstrated in the DIII-D tokamak [E. J. Strait et al., Phys. Plasmas 11, 2505 (2004)]. It is shown that the rotational stabilization observed in these experiments can be reproduced in this model if the mode is forced to rotate with a frequency above a critical level. The analytical estimates show that this effect (absent in the model based on the thin-wall approximation) is strong at realistic parameters. The model also predicts that the locking of the rotationally stabilized mode gives rise to instability with a growth rate much larger than its thin-wall estimate.

  14. Current/Pressure Profile Effects on Tearing Mode Stability in DIII-D Hybrid Discharges

    NASA Astrophysics Data System (ADS)

    Kim, K.; Park, J. M.; Murakami, M.; La Haye, R. J.; Na, Yong-Su

    2015-11-01

    It is important to understand the onset threshold and the evolution of tearing modes (TMs) for developing a high-performance steady state fusion reactor. As initial and basic comparisons to determine TM onset, the measured plasma profiles (such as temperature, density, rotation) were compared with the calculated current profiles between a pair of discharges with/without n=1 mode based on the database for DIII-D hybrid plasmas. The profiles were not much different, but the details were analyzed to determine their characteristics, especially near the rational surface. The tearing stability index calculated from PEST3, Δ' tends to increase rapidly just before the n=1 mode onset for these cases. The modeled equilibrium with varying pressure or current profiles parametrically based on the reference discharge is reconstructed for checking the onset dependency on Δ' or neoclassical effects such as bootstrap current. Simulations of TMs with the modeled equilibrium using resistive MHD codes will also be presented and compared with experiments to determine the sensibility for predicting TM onset. Work supported by US DOE under DE-FC02-04ER54698 and DE-AC52-07NA27344.

  15. Solvent friction effects propagate over the entire protein molecule through low-frequency collective modes.

    PubMed

    Moritsugu, Kei; Kidera, Akinori; Smith, Jeremy C

    2014-07-24

    Protein solvation dynamics has been investigated using atom-dependent Langevin friction coefficients derived directly from molecular dynamics (MD) simulations. To determine the effect of solvation on the atomic friction coefficients, solution and vacuum MD simulations were performed for lysozyme and staphylococcal nuclease and analyzed by Langevin mode analysis. The coefficients thus derived are roughly correlated with the atomic solvent-accessible surface area (ASA), as expected from the fact that friction occurs as the result of collisions with solvent molecules. However, a considerable number of atoms with higher friction coefficients are found inside the core region. Hence, the influence of solvent friction propagates into the protein core. The internal coefficients have large contributions from the low-frequency modes, yielding a simple picture of the surface-to-core long-range damping via solvation governed by collective low-frequency modes. To make use of these findings in implicit-solvent modeling, we compare the all-atom friction results with those obtained using Langevin dynamics (LD) with two empirical representations: the constant-friction and the ASA-dependent (Pastor-Karplus) friction models. The constant-friction model overestimates the core and underestimates the surface damping whereas the ASA-dependent friction model, which damps protein atoms only on the solvent-accessible surface, reproduces well the friction coefficients for both the surface and core regions observed in the explicit-solvent MD simulations. Therefore, in LD simulation, the solvent friction coefficients should be imposed only on the protein surface.

  16. Mode locking effects on the playing frequency for fork fingerings on the clarinet.

    PubMed

    Nederveen, C J; Dalmont, J-P

    2012-01-01

    The non-linear excitation of wind instruments generates higher harmonics of the playing frequency. These higher harmonics are coupled to resonances in the pipe. This is called mode locking. When the pipe modes are not harmonic, the playing frequency shifts away from the fundamental in order to maximize the output. It may go up or down, depending on the position of the modes and the amplitude. The effect is especially manifest for fork fingerings. Three fork fingerings on a clarinet were investigated. They were artificially blown between the threshold and extinction pressure. A time domain simulation was carried out based on a lumped model of the excitation coupled to an input impedance calculated from the instrument dimensions. At low amplitudes the fundamental frequency dominates and the playing frequency is governed by the position of the first peak in the input impedance spectra. At higher blowing pressures the playing frequency shifts. For both blowing and simulation this follows the same pattern. The frequencies predicted by the calculations are higher than the values found by blowing, which may be due to inadequacies in the model description, to uncertainties of the various parameters, as reed stiffness, moving reed area, and the properties of the slit flow.

  17. [Effect of afforestation modes on soil microbial community and nitrogen functional genes in Hippophae rhamnoides plantation].

    PubMed

    Yang, Dan; Yu, Xuan; Liu, Xu; Liu, Jin-liana; Zhang, Shun-xiang; Yu, Ze-qun

    2015-12-01

    The study aimed to assess the effect of different afforestation modes on microbial composition and nitrogen functional genes in soil. Soil samples from a pure Hippophae rhamnoides stand (SS) and three mixed stands, namely, H. rhamnoides and Pinus tabuliformis (SY), H. rhamnoides and Platycladus orientalis (SB), H. rhamnoides and Robinia pseucdoacacia (SC) were selected. The results showed that the total PLFA (TPLFA), bacterial PLFA, gram positive bacterial PLFA (G⁺PLFA) were significantly higher in soil samples from other three stands than those of the pure one. However, no significant difference was found for fungal PLFA among them. The abundance of nifH, amoA, nirK and narG genes were higher in SY and SC than in SS. The TPLFA, G⁺PLFA, gram negative bacterial PLFA (G⁻PLFA), and all of the detected gene abundance were significantly and positively correlated with soil pH, total organic carbon, total nitrogen, ammonium nitrogen and available potassium. Afforestation modes affected indirectly soil microbial composition and functional genes through soil properties. Mixing P. tabuliformis or P. orientalis with H. rhamnoides might be suitable afforestation modes, which might improve soil quality.

  18. Effects of chromium(III and VI) on spring barley and maize biomass yield and content of nitrogenous compounds.

    PubMed

    Wyszkowski, Mirosław; Radziemska, Maja

    2010-01-01

    The aim of this study was to (1) determine the effects of trivalent Cr(III) or hexavalent chromium Cr(VI) soil contamination on biomass yield and nitrogenous compound content of spring barley (Hordeum vulgare L.) as the main crop and subsequently maize (Zea mays L.) grown successively, and (2) examine whether the neutralizing additives applied (compost, zeolite, and calcium oxide) may be effective in reducing adverse impact of chromium (Cr) on crops. Spring barley yield was markedly decreased by Cr compounds, particularly Cr(VI). In contrast, maize yield was significantly increased by Cr(VI). Hexavalent Cr exerted a greater effect than the Cr(III) form on nitrogen levels in spring barley. Chromium significantly increased ammonia nitrogen content in maize. The accumulation of NO(3)(-)-N in plants treated with Cr(VI) was lower than in controls. The application of compost, zeolite, and calcium oxide onto the soil increased yield of maize only in pots containing Cr(III). Neutralizing additives exerted a positive, increased effect on the N-total content of maize but not spring barley, which was apparent with calcium oxide. Accumulation of NH(4)(+)-N in maize in pots with Cr(VI) was increased by all additives applied. The content of nitrate nitrogen in spring barley was predominantly affected by addition of compost and calcium oxide into the soil, producing a significant rise in NO(3)(-)-N content. Chromium, especially Cr(VI), used at doses of 100 and 150 mg/kg soil exerted adverse effects in treated plants, particularly spring barley.

  19. Effect of nitrate enrichment and diatoms on the bioavailability of Fe(III) oxyhydroxide colloids in seawater.

    PubMed

    Liu, Feng-Jiao; Huang, Bang-Qin; Li, Shun-Xing; Zheng, Feng-Ying; Huang, Xu-Guang

    2016-03-01

    The photoconversion of colloidal iron oxyhydroxides was a significant source of bioavailable iron in coastal systems. Diatoms dominate phytoplankton communities in coastal and upwelling regions. Diatoms are often exposed to eutrophication. We investigated the effects of different species of diatom, cell density, illumination period, and nitrate additions on the bioavailability of Fe(III) oxy-hydroxide colloids in seawaters. With the increase of illumination period from 1 to 4 h, the ratios of concentrations of total dissolved Fe (DFe) to colloidal iron oxyhydroxides and Fe(II) to DFe increased up to 24.3% and 23.9% for seawater without coastal diatoms, 45.6% and 30.2% for Skeletonema costatum, 44.3% and 29.7% for Thalassiosira weissflogii, respectively. The photochemical activity of coastal diatoms themselves (excluding the dissolved organic matter secreted by algae) on the species transformation of iron in seawater (including the light-induced dissolution of Fe(III) oxyhydroxide colloids and the photo-reduction of Fe(III) into Fe(II)) was confirmed for the first time. There was no significant difference of the ability of S. costatum and Thalassiosira weissflogii on the photoconversion of colloidal iron oxyhydroxides. The photoproduction of dissolved Fe(II) and DFe in the seawater with or without diatoms could be depressed by the nitrate addition.

  20. Effect of nitrate enrichment and diatoms on the bioavailability of Fe(III) oxyhydroxide colloids in seawater.

    PubMed

    Liu, Feng-Jiao; Huang, Bang-Qin; Li, Shun-Xing; Zheng, Feng-Ying; Huang, Xu-Guang

    2016-03-01

    The photoconversion of colloidal iron oxyhydroxides was a significant source of bioavailable iron in coastal systems. Diatoms dominate phytoplankton communities in coastal and upwelling regions. Diatoms are often exposed to eutrophication. We investigated the effects of different species of diatom, cell density, illumination period, and nitrate additions on the bioavailability of Fe(III) oxy-hydroxide colloids in seawaters. With the increase of illumination period from 1 to 4 h, the ratios of concentrations of total dissolved Fe (DFe) to colloidal iron oxyhydroxides and Fe(II) to DFe increased up to 24.3% and 23.9% for seawater without coastal diatoms, 45.6% and 30.2% for Skeletonema costatum, 44.3% and 29.7% for Thalassiosira weissflogii, respectively. The photochemical activity of coastal diatoms themselves (excluding the dissolved organic matter secreted by algae) on the species transformation of iron in seawater (including the light-induced dissolution of Fe(III) oxyhydroxide colloids and the photo-reduction of Fe(III) into Fe(II)) was confirmed for the first time. There was no significant difference of the ability of S. costatum and Thalassiosira weissflogii on the photoconversion of colloidal iron oxyhydroxides. The photoproduction of dissolved Fe(II) and DFe in the seawater with or without diatoms could be depressed by the nitrate addition. PMID:26766021

  1. Enhancement effects of reducing agents on the degradation of tetrachloroethene in the Fe(II)/Fe(III) catalyzed percarbonate system.

    PubMed

    Miao, Zhouwei; Gu, Xiaogang; Lu, Shuguang; Brusseau, Mark L; Yan, Ni; Qiu, Zhaofu; Sui, Qian

    2015-12-30

    In this study, the effects of reducing agents on the degradation of tetrachloroethene (PCE) were investigated in the Fe(II)/Fe(III) catalyzed sodium percarbonate (SPC) system. The addition of reducing agents, including hydroxylamine hydrochloride, sodium sulfite, ascorbic acid and sodium ascorbate, accelerated the Fe(III)/Fe(II) redox cycle, leading to a relatively steady Fe(II) concentration and higher production of free radicals. This, in turn, resulted in enhanced PCE oxidation by SPC, with almost complete PCE removal obtained for appropriate Fe and SPC concentrations. The chemical probe tests, using nitrobenzene and carbon tetrachloride, demonstrated that HO was the predominant radical in the system and that O2(-) played a minor role, which was further confirmed by the results of electron spin resonance measurements. PCE degradation decreased significantly with the addition of isopropanol, a HO scavenger, supporting the hypothesis that HO was primarily responsible for PCE degradation. It is noteworthy that Cl(-) release was slightly delayed in the first 20 min, indicating that intermediate products were produced. However, these intermediates were further degraded, resulting in the complete conversion of PCE to CO2. In conclusion, the use of reducing agents to enhance Fe(II)/Fe(III) catalyzed SPC oxidation appears to be a promising approach for the rapid degradation of organic contaminants in groundwater. PMID:26257094

  2. Enhancement effects of reducing agents on the degradation of tetrachloroethene in the Fe(II)/Fe(III) catalyzed percarbonate system.

    PubMed

    Miao, Zhouwei; Gu, Xiaogang; Lu, Shuguang; Brusseau, Mark L; Yan, Ni; Qiu, Zhaofu; Sui, Qian

    2015-12-30

    In this study, the effects of reducing agents on the degradation of tetrachloroethene (PCE) were investigated in the Fe(II)/Fe(III) catalyzed sodium percarbonate (SPC) system. The addition of reducing agents, including hydroxylamine hydrochloride, sodium sulfite, ascorbic acid and sodium ascorbate, accelerated the Fe(III)/Fe(II) redox cycle, leading to a relatively steady Fe(II) concentration and higher production of free radicals. This, in turn, resulted in enhanced PCE oxidation by SPC, with almost complete PCE removal obtained for appropriate Fe and SPC concentrations. The chemical probe tests, using nitrobenzene and carbon tetrachloride, demonstrated that HO was the predominant radical in the system and that O2(-) played a minor role, which was further confirmed by the results of electron spin resonance measurements. PCE degradation decreased significantly with the addition of isopropanol, a HO scavenger, supporting the hypothesis that HO was primarily responsible for PCE degradation. It is noteworthy that Cl(-) release was slightly delayed in the first 20 min, indicating that intermediate products were produced. However, these intermediates were further degraded, resulting in the complete conversion of PCE to CO2. In conclusion, the use of reducing agents to enhance Fe(II)/Fe(III) catalyzed SPC oxidation appears to be a promising approach for the rapid degradation of organic contaminants in groundwater.

  3. [Effects of different irrigation modes on winter wheat grain yield and water- and nitrogen use efficiency].

    PubMed

    Men, Hong-wen; Zhang, Qiu; Dai, Xing-long; Cao, Qian; Wang, Cheng-yu; Zhou, Xiao-hu; He, Ming-rong

    2011-10-01

    Taking the widely planted winter wheat cultivar Tainong 18 as test material, a field experiment was conducted to study the effects of different irrigation modes on the winter wheat grain yield and water- and nitrogen use efficiency in drier year (2009-2010) in Tai' an City of Shandong Province, China. Five treatments were installed, i. e., irrigation before sowing (CK), irrigation before sowing and at jointing stage (W1), irrigation before sowing and at jointing stages and at over-wintering stage with alternative irrigation at milking stage (W2), irrigation before sowing and at jointing and flowering stages (optimized traditional irrigation mode, W3), and irrigation before sowing and at over-wintering, jointing, and milking stages (traditional irrigation mode, W4). The irrigation amount was 600 m3 hm(-2) one time. Under the condition of 119.7 mm precipitation in the winter wheat growth season, no significant difference was observed in the grain yield between treatments W2 and W4, but the water use efficiency was significantly higher in W2 than in W4. Comparing with treatment W3, treatments W2 and W4 had obviously higher grain yield, but the water use efficiency had no significant difference. The partial factor productivity from N fertilization was the highest in W2 and W4, and the NO3(-)-N accumulation amount in 0-100 cm soil layer at harvest was significantly higher in W2 than in W3 and W4, suggesting that W2 could reduce NO3(-)-N leaching loss. Under the conditions of our experiment, irrigation before sowing and jointing stages and at over-wintering stage with alternative irrigation at milking stage was the optimal irrigation mode in considering both the grain yield and the water- and nitrogen use efficiency.

  4. NON-WKB MODELS OF THE FIRST IONIZATION POTENTIAL EFFECT: THE ROLE OF SLOW MODE WAVES

    SciTech Connect

    Laming, J. Martin

    2012-01-10

    A model for element abundance fractionation between the solar chromosphere and corona is further developed. The ponderomotive force due to Alfven waves propagating through or reflecting from the chromosphere in solar conditions generally accelerates chromospheric ions, but not neutrals, into the corona. This gives rise to what has become known as the first ionization potential effect. We incorporate new physical processes into the model. The chromospheric ionization balance is improved and the effect of different approximations is discussed. We also treat the parametric generation of slow mode waves by the parallel propagating Alfven waves. This is also an effect of the ponderomotive force, arising from the periodic variation of the magnetic pressure driving an acoustic mode, which adds to the background longitudinal pressure. This can have subtle effects on the fractionation, rendering it quasi-mass independent in the lower regions of the chromosphere. We also briefly discuss the change in the fractionation with Alfven wave frequency, relative to the frequency of the overlying coronal loop resonance.

  5. Dead time effects in turbulence spectra measured by burst-mode LDA

    NASA Astrophysics Data System (ADS)

    Velte, Clara; Buchhave, Preben; George, William

    2014-11-01

    Dead time effects in laser Doppler measurements have not so far been considered a major problem. We show how dead time occurs in burst-mode laser Doppler anemometry (LDA) when using a so-called burst-mode LDA processor and describe their effects on the measured power spectra. We show how dead time effects may be caused by more than one seed particle being present in the measurement volume at the same time and explain analytically how dead time causes a reduction in the power in the spectrum at low frequencies and an oscillation in the spectrum at the high frequency end. We also present a realistic model for the data sampled from a processor with dead time and use this model to generate turbulence velocity data in a computer. Finally we compare the spectrum computed from realistic values of dead time and sample rate in the computer generated data and compare this spectrum to a measured spectrum in a free turbulent jet with similar parameters. The excellent agreement between the features of these spectra show that our model and explanation of the dead time effect is a valid one.

  6. Effect of heat flux on Alfvén ballooning modes in isotropic Hall-MHD plasmas

    NASA Astrophysics Data System (ADS)

    Ma, John Z. G.; Hirose, Akira; Liu, William W.

    2014-12-01

    The magnetosphere undergoes a transition from a dipole-like to taillike structure in the antisunward direction. In this region, Alfvén ballooning instability has been considered as a leading candidate to be responsible for the onset and expansion phase of observed impulsive substorms. We apply the generalized Ohm's law in isotropic Hall-MHD equations and study the effect of heat flux on the ballooning modes under substorm circumstances. The set of partial differential equations is obtained for a general ballooning dispersion relation from which all classical Alfvén waves and fundamental ballooning modes are recovered, e.g., the decoupled shear Alfvén and magnetosonic modes, the classical ballooning instability in incompressible plasmas. In the absence of the heat flux, the ballooning mode is featured by the coupling of the two modes by the superposition of the independent Hall effect and the independent plasma inhomogeneity effect. By contrast, heat flux exerts its influence on the ballooning mode by updating the coefficients of the terms in the dispersion relation. The results expose that the growth rate (γBM) has two branches. If kp is β free, one branch shifts versus β, while the other branch is damped substantially by the heat flux, leading to a more stable ballooning mode; if kc is β free, one branch shifts little versus β, but the other one has higher γBM driven by the heat flux, leading to a more unstable ballooning mode.

  7. Structural insights into the counterion effects on the manganese(III) spin crossover system with hexadentate Schiff-base ligands.

    PubMed

    Wang, Shi; Xu, Wu-Tan; He, Wen-Rui; Takaishi, Shinya; Li, Yong-Hua; Yamashita, Masahiro; Huang, Wei

    2016-04-01

    A series of new salts [Mn(5-MeO-sal-N-1,5,8,12)]Y (Y = ClO4 for 1, Y = BF4 for 2, Y = NO3 for 3 and Y = CF3SO3 for 4) based on the six-coordinated mononuclear manganese(iii) Schiff-base complex cation [Mn(5-MeO-sal-N-1,5,8,12)](+), has been investigated to determine the impact of counter anion effects, intramolecular ligand distortion and intermolecular supramolecular structures on the spin crossover (SCO) behavior. The SCO in salt 1 has resulted in a crystallographic observation of the coexistence of high-spin (HS, S = 2) and low-spin (LS, S = 1) manganese(iii) complex cations in equal proportions around 100 K. At room temperature, the two crystallographically distinct manganese centers are both close to the complete HS state. Only one of the two slightly different units undergoes SCO in the temperature range 300-180 K, whereas the other remains in the HS state down to 20 K. For salts 2 and 3, crystal structural analysis indicates change in the anion from ClO4(-) to BF4(-) and NO3(-) was led to the close arrangement of the cations and the stacking between phenyl groups from the ligands. With CF3SO3(-) as the counterion, although the cations and the anions separate clearly in one direction, the close arrangement of cations in other directions precludes the spin transformation of the Mn(iii) cations. Magnetic measurements on 2-4 indicate that the manganese(iii) complex cations remain in the HS state in the temperature range 2-300 K. PMID:26927027

  8. The properties of the extraordinary mode and surface plasmon modes in the three-dimensional magnetized plasma photonic crystals based on the magneto-optical Voigt effects

    SciTech Connect

    Zhang, Hai-Feng E-mail: lsb@nuaa.edu.cn; Liu, Shao-Bin E-mail: lsb@nuaa.edu.cn; Tang, Yi-Jun

    2014-06-15

    In this paper, the properties of the extraordinary mode and surface plasmon modes in the three-dimensional (3D) magnetized plasma photonic crystals (MPPCs) with face-centered-cubic lattices that are composed of the core tellurium (Te) spheres with surrounded by the homogeneous magnetized plasma shells inserted in the air, are theoretically investigated in detail by the plane wave expansion method, as the magneto-optical Voigt effects of magnetized plasma are considered (the incidence electromagnetic wave vector is perpendicular to the external magnetic field at any time). The optical switching or wavelength division multiplexer can be realized by the proposed 3D MPPCs. Our analyses demonstrate that the complete photonic band gaps (PBGs) and two flatbands regions for the extraordinary mode can be observed obviously. PBGs can be tuned by the radius of core Te sphere, the plasma density and the external magnetic field. The flatbands regions are determined by the existence of surface plasmon modes. Numerical simulations also show that if the thickness of magnetized plasma shell is larger than a threshold value, the band structures of the extraordinary mode will be similar to those obtained from the same structure containing the pure magnetized plasma spheres. In this case, the band structures also will not be affected by the inserted core spheres. It is also provided that the upper edges of two flatbands regions will not depend on the topology of lattice. However, the frequencies of lower edges of two flatbands regions will be convergent to the different constants for different lattices, as the thickness of magnetized plasma shell is close to zero.

  9. The properties of the extraordinary mode and surface plasmon modes in the three-dimensional magnetized plasma photonic crystals based on the magneto-optical Voigt effects

    NASA Astrophysics Data System (ADS)

    Zhang, Hai-Feng; Liu, Shao-Bin; Tang, Yi-Jun

    2014-06-01

    In this paper, the properties of the extraordinary mode and surface plasmon modes in the three-dimensional (3D) magnetized plasma photonic crystals (MPPCs) with face-centered-cubic lattices that are composed of the core tellurium (Te) spheres with surrounded by the homogeneous magnetized plasma shells inserted in the air, are theoretically investigated in detail by the plane wave expansion method, as the magneto-optical Voigt effects of magnetized plasma are considered (the incidence electromagnetic wave vector is perpendicular to the external magnetic field at any time). The optical switching or wavelength division multiplexer can be realized by the proposed 3D MPPCs. Our analyses demonstrate that the complete photonic band gaps (PBGs) and two flatbands regions for the extraordinary mode can be observed obviously. PBGs can be tuned by the radius of core Te sphere, the plasma density and the external magnetic field. The flatbands regions are determined by the existence of surface plasmon modes. Numerical simulations also show that if the thickness of magnetized plasma shell is larger than a threshold value, the band structures of the extraordinary mode will be similar to those obtained from the same structure containing the pure magnetized plasma spheres. In this case, the band structures also will not be affected by the inserted core spheres. It is also provided that the upper edges of two flatbands regions will not depend on the topology of lattice. However, the frequencies of lower edges of two flatbands regions will be convergent to the different constants for different lattices, as the thickness of magnetized plasma shell is close to zero.

  10. Effect of different solutes, natural organic matter, and particulate Fe(III) on ferrate(VI) decomposition in aqueous solutions.

    PubMed

    Jiang, Yanjun; Goodwill, Joseph E; Tobiason, John E; Reckhow, David A

    2015-03-01

    This study investigated the impacts of buffer ions, natural organic matter (NOM), and particulate Fe(III) on ferrate(VI) decomposition and characterized Fe(VI) decomposition kinetics and exposure in various waters. Homogeneous and heterogeneous Fe(VI) decomposition can be described as a second- and first-order reaction with respect to Fe(VI), respectively. Fe(VI) decay was catalyzed by Fe(VI) decomposition products. Solutes capable of forming complexes with iron hydroxides retarded Fe(VI) decay. Fractionation of the resulting solutions from Fe(VI) self-decay and ferric chloride addition in borate- and phosphate-buffered waters showed that phosphate could sequester Fe(III). The nature of the iron precipitate from Fe(VI) decomposition was different from that of freshly precipitated ferric hydroxide from ferric chloride solutions. The stabilizing effects of different solutes on Fe(VI) are in the following order: phosphate > bicarbonate > borate. The constituents of colored and alkaline waters (NOM and bicarbonate) inhibited the catalytic effects of Fe(VI) decomposition products and stabilized Fe(VI) in natural waters. Because of the stabilizing effects of solutes, moderate doses of Fe(VI) added to natural waters at pH 7.5 resulted in exposures that have been shown to be effective for inactivation of target pathogens. Preformed ferric hydroxide was less effective than freshly dosed ferric chloride in accelerating Fe(VI) decomposition.

  11. Microheterogeneity of antithrombin III: effect of single amino acid substitutions and relationship with functional abnormalities.

    PubMed

    De Stefano, V; Leone, G; Mastrangelo, S; Lane, D A; Girolami, A; de Moerloose, P; Sas, G; Abildgaard, U; Blajchman, M; Rodeghiero, F

    1994-02-01

    Microheterogeneity of antithrombin III (AT-III) was investigated by crossed immunoelectrofocusing (CIEF) on eleven molecular variants. A normal pattern was found in five variants while two different abnormal CIEF patterns were found in the other four and two variants, respectively. Point mutations causing a major pI change (exceeding 4.0) of the amino acid substituted lead to alterations in the overall microheterogeneity. The variants thus substituted share a first type of abnormal CIEF pattern with alterations throughout the pH range, regardless of the location of the mutation (reactive site and adjacent regions or heparin binding region). Minor amino acid pI changes in these regions do not alter the AT-III overall microheterogeneity, whatever the resulting functional defect. However, if the mutation is placed in the region around positions 404 or 429, then even minor changes of the amino acid pI seem able to alter the overall charge, leading to a second type of abnormal CIEF pattern with the main alteration at pH 4.8-4.6. Neuraminidase treatment leads to disappearance of microheterogeneity except for the variants with the Arg393 to Cys substitution. Addition of thrombin induces CIEF modifications specifically related to the functional defect. A normal formation of thrombin-antithrombin complexes induces a shift towards the more acid pH range, whereas in the variants substituted at the reactive site the CIEF pattern is substantially unaffected by thrombin; variants substituted at positions 382-384 show a maximal thrombin-induced increase of the isoforms at pI 4.8-4.6. Therefore mutant antithrombins with different functional abnormalities but sharing a common CIEF pattern were well distinguished.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8180341

  12. Effects of commuting mode on air pollution exposure and cardiovascular health among young adults in Taipei, Taiwan.

    PubMed

    Liu, Wen-Te; Ma, Chih-Ming; Liu, I-Jung; Han, Bor-Cheng; Chuang, Hsiao-Chi; Chuang, Kai-Jen

    2015-05-01

    The association between traffic-related air pollution and adverse cardiovascular effects has been well documented; however, little is known about whether different commuting modes can modify the effects of air pollution on the cardiovascular system in human subjects in urban areas with heavy traffic. We recruited 120 young, healthy subjects in Taipei, Taiwan. Each participant was classified with different commuting modes according to his/her own commuting style. Three repeated measurements of heart rate variability (HRV) indices {standard deviation of NN intervals (SDNN) and the square root of the mean of the sum of the squares of differences between adjacent NN intervals (r-MSSD)}, particulate matter with an aerodynamic diameter ≤ 2.5 μm (PM2.5), temperature, humidity and noise level were conducted for each subject during 1-h morning commutes (0900-1000 h) in four different commuting modes, including an electrically powered subway, a gas-powered bus, a gasoline-powered car, and walking. Linear mixed-effects models were used to investigate the association of PM2.5 with HRV indices. The results showed that decreases in the HRV indices were associated with increased levels of PM2.5. The personal exposure levels to PM2.5 were the highest in the walking mode. The effects of PM2.5 on cardiovascular endpoints were the lowest in the subway mode compared to the effects in the walking mode. The participants in the car and bus modes had reduced effects on their cardiovascular endpoints compared to the participants in the walking mode. We concluded that traffic-related PM2.5 is associated with autonomic alteration. Commuting modes can modify the effects of PM2.5 on HRV indices among young, healthy subjects. PMID:25638696

  13. Effects of commuting mode on air pollution exposure and cardiovascular health among young adults in Taipei, Taiwan.

    PubMed

    Liu, Wen-Te; Ma, Chih-Ming; Liu, I-Jung; Han, Bor-Cheng; Chuang, Hsiao-Chi; Chuang, Kai-Jen

    2015-05-01

    The association between traffic-related air pollution and adverse cardiovascular effects has been well documented; however, little is known about whether different commuting modes can modify the effects of air pollution on the cardiovascular system in human subjects in urban areas with heavy traffic. We recruited 120 young, healthy subjects in Taipei, Taiwan. Each participant was classified with different commuting modes according to his/her own commuting style. Three repeated measurements of heart rate variability (HRV) indices {standard deviation of NN intervals (SDNN) and the square root of the mean of the sum of the squares of differences between adjacent NN intervals (r-MSSD)}, particulate matter with an aerodynamic diameter ≤ 2.5 μm (PM2.5), temperature, humidity and noise level were conducted for each subject during 1-h morning commutes (0900-1000 h) in four different commuting modes, including an electrically powered subway, a gas-powered bus, a gasoline-powered car, and walking. Linear mixed-effects models were used to investigate the association of PM2.5 with HRV indices. The results showed that decreases in the HRV indices were associated with increased levels of PM2.5. The personal exposure levels to PM2.5 were the highest in the walking mode. The effects of PM2.5 on cardiovascular endpoints were the lowest in the subway mode compared to the effects in the walking mode. The participants in the car and bus modes had reduced effects on their cardiovascular endpoints compared to the participants in the walking mode. We concluded that traffic-related PM2.5 is associated with autonomic alteration. Commuting modes can modify the effects of PM2.5 on HRV indices among young, healthy subjects.

  14. Hepatotoxicity of Pentavalent Antimonial Drug: Possible Role of Residual Sb(III) and Protective Effect of Ascorbic Acid

    PubMed Central

    Kato, Kelly C.; Morais-Teixeira, Eliane; Reis, Priscila G.; Silva-Barcellos, Neila M.; Salaün, Pascal; Campos, Paula P.; Dias Corrêa-Junior, José; Rabello, Ana; Demicheli, Cynthia

    2014-01-01

    Pentavalent antimonial drugs such as meglumine antimoniate (Glucantime [Glu; Sanofi-Aventis, São Paulo, Brazil]) produce severe side effects, including cardiotoxicity and hepatotoxicity, during the treatment of leishmaniasis. We evaluated the role of residual Sb(III) in the hepatotoxicity of meglumine antimoniate, as well as the protective effect of the antioxidant ascorbic acid (AA) during antimonial chemotherapy in a murine model of visceral leishmaniasis. BALB/c mice infected with Leishmania infantum were treated intraperitoneally at 80 mg of Sb/kg/day with commercial meglumine antimoniate (Glu) or a synthetic meglumine antimoniate with lower Sb(III) level (MA), in association or not with AA (15 mg/kg/day), for a 20-day period. Control groups received saline or saline plus AA. Livers were evaluated for hepatocytes histological alterations, peroxidase activity, and apoptosis. Increased proportions of swollen and apoptotic hepatocytes were observed in animals treated with Glu compared to animals treated with saline or MA. The peroxidase activity was also enhanced in the liver of animals that received Glu. Cotreatment with AA reduced the extent of histological changes, the apoptotic index, and the peroxidase activity to levels corresponding to the control group. Moreover, the association with AA did not affect the hepatic uptake of Sb and the ability of Glu to reduce the liver and spleen parasite loads in infected mice. In conclusion, our data supports the use of pentavalent antimonials with low residue of Sb(III) and the association of pentavalent antimonials with AA, as effective strategies to reduce side effects in antimonial therapy. PMID:24189251

  15. [Effects of different root zone irrigation modes on apple seedlings hydraulic resistance].

    PubMed

    Yang, Qi-liang; Zhang, Fu-cang

    2009-01-01

    This paper studied the effects of different root zone irrigation modes (alternate partial drip irrigation, ADI; fixed partial drip irrigation, FDI; and conventional drip irrigation, CDI) and their watering amount on the whole-plant and its components hydraulic resistance and the stomata conductance and leaf area of apple seedlings. The results showed that both the irrigation mode and the watering amount had significant effects on the apple seedlings hydraulic resistance (R). Under the same irrigation modes, the root resistance (Rr) of apple seedlings was increased, but the shoot resistance (Rs) was decreased with decreasing watering amount; and under the same watering amounts, ADI and FDI increased the leaf and petiole resistance (R(1+p)), but decreased the whole-plant resistance (Rt), Rr, Rs, and lateral branch and master rod resistance (R(lb+mr)), compared with CDI. Under the irrigation quota of 20 mm and 30 mm, the R(l+p) of ADI was 1.06% and 0.63% higher than that of CDI, respectively; and with the prerequisite of saving 33% of irrigation water, the average R(l+p) of ADI and FDI was increased by 19.65% and 24.34%, while the average R(lb+mr) was decreased by 4.83% and 14.97%, respectively, compared with those of CDI. ADI and FDI effectively decreased stomata conductance and leaf area and increased R(l+p), and thus, decreased leaf blade luxurious transpiration dehydration while increased plant water use efficiency. By decreasing Rr and R(lb+mr), the ADI and FDI improved apple seedlings water regulation function and drought-resistant capability.

  16. Bonding and Anti-bonding Modes of Plasmon Coupling Effects in TiO2-Ag Core-shell Dimers

    PubMed Central

    Li, Quanshui; Zhang, Zhili

    2016-01-01

    Bonding and anti-bonding modes of plasmon coupling effects are numerically investigated in TiO2-Ag core-shell nano dimers. First, splitting phenomena of the coupled anti-bonding modes are observed under the longitudinal polarization when the distance between the monomers decreases to a certain level. Second, one of the split resonance modes is identified to be formed by the dipole anti-bonding mode of the monomers from charge density distribution patterns. Those split modes have similar redshift behaviors as the coupled dipole bonding modes in the same situations. Furthermore, the intensities of those anti-bonding modes weaken with decreasing distance between the monomers, because of the interaction of the induced dipole moment in the monomers and the charge distribution variation on the facing surfaces of the gap by the coulomb attraction. Other split bands are the higher-order mode (octupole-like or triakontadipole-like), which do not have obvious peak-shift behavior, and the intensities have very little attenuation with decreasing distance. Finally, the coupling of the bonding and anti-bonding modes under the longitudinal polarization is symmetric (bonding). PMID:26763719

  17. Bonding and Anti-bonding Modes of Plasmon Coupling Effects in TiO2-Ag Core-shell Dimers.

    PubMed

    Li, Quanshui; Zhang, Zhili

    2016-01-01

    Bonding and anti-bonding modes of plasmon coupling effects are numerically investigated in TiO2-Ag core-shell nano dimers. First, splitting phenomena of the coupled anti-bonding modes are observed under the longitudinal polarization when the distance between the monomers decreases to a certain level. Second, one of the split resonance modes is identified to be formed by the dipole anti-bonding mode of the monomers from charge density distribution patterns. Those split modes have similar redshift behaviors as the coupled dipole bonding modes in the same situations. Furthermore, the intensities of those anti-bonding modes weaken with decreasing distance between the monomers, because of the interaction of the induced dipole moment in the monomers and the charge distribution variation on the facing surfaces of the gap by the coulomb attraction. Other split bands are the higher-order mode (octupole-like or triakontadipole-like), which do not have obvious peak-shift behavior, and the intensities have very little attenuation with decreasing distance. Finally, the coupling of the bonding and anti-bonding modes under the longitudinal polarization is symmetric (bonding). PMID:26763719

  18. A Review of Healthcare Failure Mode and Effects Analysis (HFMEA) in Radiotherapy.

    PubMed

    Giardina, M; Cantone, M C; Tomarchio, E; Veronese, I

    2016-10-01

    This paper presents a review of risk analyses in radiotherapy (RT) processes carried out by using Healthcare Failure Mode Effect Analysis (HFMEA) methodology, a qualitative method that proactively identifies risks to patients and corrects medical errors before they occur. This literature review was performed to provide an overview of how to approach the development of HFMEA applications in modern RT procedures, comparing recently published research conducted to support proactive programs to identify risks. On the basis of the reviewed literature, the paper suggests HFMEA shortcomings that need to be addressed. PMID:27575344

  19. Ga(III) complexes as models for the M(III) site of purple acid phosphatase: ligand effects on the hydrolytic reactivity toward bis(2,4-dinitrophenyl) phosphate.

    PubMed

    Coleman, Fergal; Hynes, Michael J; Erxleben, Andrea

    2010-07-19

    The effects of a series of Ga(III) complexes with tripodal ligands on the hydrolysis rate of the activated phosphate diester bis(2,4-dinitrophenyl)phosphate (BDNPP) have been investigated. In particular, the influence of the nature of the ligand donor sites on the reactivity of Ga(III) which represents a mimic of the Fe(III) ion in purple acid phosphatase has been evaluated. It has been shown that replacing neutral nitrogen donor atoms and carboxylate groups by phenolate groups enhanced the reactivity of the Ga complexes. Bell-shaped pH-rate profiles and the measured solvent deuterium isotope effects are indicative of a mechanism that involves nucleophilic attack on the coordinated substrate by Ga-OH. The trend in reactivity found for the different Ga complexes reveals that of the two effects of the metal, Lewis acid activation of the substrate and nucleophile activation, the latter one is more important in determining the intrinsic reactivity of the metal catalyst. The relevance of the present findings for the modulation of the activity of the M(III) ion in purple acid phosphatase whose active site contains a phenolate (tyrosine side chain) is discussed. PMID:20565083

  20. The stray capacitance effect in Kelvin probe force microscopy using FM, AM and heterodyne AM modes.

    PubMed

    Ma, Zong Min; Kou, Lili; Naitoh, Yoshitaka; Li, Yan Jun; Sugawara, Yasuhiro

    2013-06-01

    The effect of stray capacitance on potential measurements was investigated using Kelvin probe force microscopy (KPFM) at room temperature under ultra-high vacuum (UHV). The stray capacitance effect was explored in three modes, including frequency modulation (FM), amplitude modulation (AM) and heterodyne amplitude modulation (heterodyne AM). We showed theoretically that the distance-dependence of the modulated electrostatic force in AM-KPFM is significantly weaker than in FM- and heterodyne AM-KPFMs and that the stray capacitance of the cantilever, which seriously influences the potential measurements in AM-KPFM, was almost completely eliminated in FM- and heterodyne AM-KPFMs. We experimentally confirmed that the contact potential difference (CPD) in AM-KPFM, which compensates the electrostatic force between the tip and the surface, was significantly larger than in FM- and heterodyne AM-KPFMs due to the stray capacitance effect. We also compared the atomic scale corrugations in the local contact potential difference (LCPD) among the three modes on the surface of Si(111)-7 × 7 finding that the LCPD corrugation in AM-KPFM was significantly weaker than in FM- and heterodyne AM-KPFMs under low AC bias voltage conditions. The very weak LCPD corrugation in AM-KPFM was attributed to the artefact induced by topographic feedback.

  1. Criterion for mixed mode fracture in composite bonded joints

    NASA Technical Reports Server (NTRS)

    Mall, S.; Kochhar, N. K.

    1986-01-01

    A study was undertaken to characterize the debond growth mechanism of adhesively bonded composite joints under mode I, mixed mode I-II, and mode II static loadings. The bonded system consisted of graphite-epoxy composite adherends bonded with a toughened epoxy adhesive. The mode I, mode II and mixed mode I-II fracture energies of the tested adhesives were found to be equal to each other. The criterion for mixed mode fracture in composite bonded joints was found.

  2. In vitro anti-leishmanial and anti-fungal effects of new SbIII carboxylates

    PubMed Central

    2011-01-01

    Ring opening of phthalic anhydride has been carried out in acetic acid with glycine, β-alanine, L-phenylalanine, and 4-aminobenzoic acid to yield, respectively, 2-{[(carboxymethyl)amino]carbonyl}benzoic acid (I), 2-{[(2-carboxyethyl)amino]carbonyl}benzoic acid (II), 2-{[(1-carboxy-2-phenylethyl)amino]carbonyl}benzoic acid (III), and 2-[(4-carboxyanilino)carbonyl]benzoic acid (IV). Compounds I-IV have been employed as ligands for Sb(III) center (complexes V-VIII) in aqueous medium. FTIR and 1H NMR spectra proved the deprotonation of carboxylic protons and coordination of imine group and thereby tridentate behaviour of the ligands as chelates. Elemental, MS, and TGA analytic data confirmed the structural hypothesis based on spectroscopic results. All the compounds have been assayed in vitro for anti-leishmanial and anti-fungal activities against five leishmanial strains L. major (JISH118), L. major (MHOM/PK/88/DESTO), L. tropica (K27), L. infantum (LEM3437), L. mex mex (LV4), and L. donovani (H43); and Aspergillus Flavus, Aspergillus Fumigants, Aspergillus Niger, and Fusarium Solani. Compound VII exhibited good anti-leishmanial as well as anti-fungal impacts comparable to reference drugs.

  3. Effect of type III antifreeze protein dilution and mutation on the growth inhibition of ice.

    PubMed Central

    DeLuca, C I; Chao, H; Sönnichsen, F D; Sykes, B D; Davies, P L

    1996-01-01

    Mutation of residues at the ice-binding site of type III antifreeze protein (AFP) not only reduced antifreeze activity as indicated by the failure to halt ice crystal growth, but also altered ice crystal morphology to produce elongated hexagonal bipyramids. In general, the c axis to a axis ratio of the ice crystal increased from approximately 2 to over 10 with the severity of the mutation. It also increased during ice crystal growth upon serial dilution of the wild-type AFP. This is in marked contrast to the behavior of the alpha-helical type I AFPs, where neither dilution nor mutation of ice-binding residues increases the c:a axial ratio of the ice crystal above the standard 3.3. We suggest that the ice crystal morphology produced by type III AFP and its mutants can be accounted for by the protein binding to the prism faces of ice and operating by step growth inhibition. In this model a decrease in the affinity of the AFP for ice leads to filling in of individual steps at the prism surfaces, causing the ice crystals to grow with a longer c:a axial ratio. Images FIGURE 3 FIGURE 4 PMID:8913575

  4. Effects of a random spatial variation of the plasma density on the mode conversion in cold, unmagnetized, and stratified plasmas

    SciTech Connect

    Jung Yu, Dae; Kim, Kihong

    2013-12-15

    We study the effects of a random spatial variation of the plasma density on the mode conversion of electromagnetic waves into electrostatic oscillations in cold, unmagnetized, and stratified plasmas. Using the invariant imbedding method, we calculate precisely the electromagnetic field distribution and the mode conversion coefficient, which is defined to be the fraction of the incident wave power converted into electrostatic oscillations, for the configuration where a numerically generated random density variation is added to the background linear density profile. We repeat similar calculations for a large number of random configurations and take an average of the results. We obtain a peculiar nonmonotonic dependence of the mode conversion coefficient on the strength of randomness. As the disorder increases from zero, the maximum value of the mode conversion coefficient decreases initially, then increases to a maximum, and finally decreases towards zero. The range of the incident angle in which mode conversion occurs increases monotonically as the disorder increases. We present numerical results suggesting that the decrease of mode conversion mainly results from the increased reflection due to the Anderson localization effect originating from disorder, whereas the increase of mode conversion of the intermediate disorder regime comes from the appearance of many resonance points and the enhanced tunneling between the resonance points and the cutoff point. We also find a very large local enhancement of the magnetic field intensity for particular random configurations. In order to obtain high mode conversion efficiency, it is desirable to restrict the randomness close to the resonance region.

  5. [Effects of labor-saving rice cultivation modes on the diversity of potential weed communities in paddy fields].

    PubMed

    Li, Shu-Shun; Qiang, Sheng; Jiao, Jun-Sen

    2009-10-01

    Aimed to understand the effects of various labor-saving rice cultivation modes on the diversity of potential weed communities in paddy fields, an investigation was made on the quantitative characteristics of the weed seed bank under dry direct seeding, water direct seeding, seedling throwing, mechanized-transplanting, wheat-rice interplanting, and conventional manual transplanting. Under dry direct seeding, the density of the weed seed bank was up to 228,416 seeds x m(-2), being significantly higher than that under the other five cultivation modes. Wheat-rice interplanting ranked the second place. The seed density of sedge weeds under dry direct seeding and that of broad leaf weeds under wheat-rice interplanting were significantly higher than the seed densities of various kinds of weeds under other cultivation modes. Conventional manual transplanting mode had the highest species richness, with Margalef index being 1.86. The diversity indices, including Shannon-Wiener index, Gini index, and Pielou evenness index under water direct seeding and wheat-rice interplanting were higher than those under other cultivation modes. Comparing with conventional manual transplanting mode, the other five cultivation modes had their own dominant species in the potential weed community, and thereby, different labor-saving rice cultivation modes should be applied by turns to control the potential weed community in paddy fields effectively and persistently.

  6. Cytotoxic effects of the compound cis-tetraammine(oxalato)ruthenium(III) dithionate on K-562 human chronic myelogenous leukemia cells.

    PubMed

    Pereira, Flávia de Castro; de Lima, Aliny Pereira; Vilanova-Costa, Cesar Augusto Sam Tiago; Pires, Wanessa Carvalho; Ribeiro, Alessandra de Santana Braga Barbosa; Pereira, Lucas Carlos Gomes; Pavanin, Luiz Alfredo; Dos Santos, Wagner Batista; Silveira-Lacerda, Elisângela de Paula

    2014-01-01

    Chemotherapy is a common treatment for leukemia. Ruthenium complexes have shown potential utility in chemotherapy and photodynamic therapy. The identification of new chemotherapeutics agents is critical for further progress in the treatment of leukemia. Ruthenium complexes generally have lower toxicities compared to cisplatin attributed to their specific accumulation in cancer tissues. Based on these evidences, in the present work we studied the cytotoxic activity of the ruthenium(III) compound cis-tetraammine(oxalato)ruthenium(III) dithionate - {cis-[Ru(C2O4)(NH3)4]2(S2O6)} against human chronic myelogenous leukemia cells (K-562) tumor cell line. The tested compound induces cell death in a dose and time dependent manner on K-562 cells. It is found that the effect was improved linearly while prolonging the incubation time. Compared to the cell cycle profiles of untreated cells, flow cytometric analysis indicated the sub-G1 arresting effect of ruthenium compound on K-562 cells. In our study, {cis-[Ru(C2O4)(NH3)4]2(S2O6)} shows a significant increase in tailed cells in any of the concentrations tested compared with negative control. Consequently, the concentration of {cis-[Ru(C2O4)(NH3)4]2(S2O6)} might be associated cytotoxicity with direct effect on K-562 cells DNA. Thus, it can be deducted that ruthenium-based compounds present selectivity to enter both tumor and normal cells. Additional studies are needed to determine the molecular mechanisms of the active components and to evaluate the potential in vivo anticancer activity of the cis-tetraammine(oxalato)ruthenium(III) dithionate.

  7. Rapid Ti(III) reduction of perchlorate in the presence of beta-alanine: kinetics, pH effect, complex formation, and beta-alanine effect.

    PubMed

    Wang, Chao; Huang, Zhengdao; Lippincott, Lee; Meng, Xiaoguang

    2010-03-15

    Ti(III) reduction of perchlorate might be a useful method for the treatment of highly perchlorate-contaminated water. Though the reaction rate was usually low, we observed that beta-alanine (HOOCCH(2)CH(2)NH(2)) could significantly promote the reaction. A complete (>99.9%) perchlorate removal was obtained in a solution containing [ClO(4)(-)]=1.0mM, [Ti(III)]=40 mM, and [beta-alanine]=120 mM after 2.5h of reaction under 50 degrees C. The effects of both pH and complex formation on the reaction were then studied. The results showed that without beta-alanine the optimal pH was 2.3. When pH increased from 1.6 to 2.3, the reduction rate increased remarkably. In the pH range >2.3, however, the reduction was significantly inhibited, attributed to the formation of Ti(III) precipitate. The presence of beta-alanine at a molar ratio of [beta-alanine]:[Ti(III)]=3:1 significantly increased the reduction rate of perchlorate even at near neutral pH. This is because beta-alanine formed complexes with Ti(III), which greatly improved the total soluble [Ti(III)] in the pH range between 3.5 and 6. The findings may lead to the development of rapid treatment methods for intermittent and small stream of highly perchlorate-contaminated water, which are resulted from the manufacturing, storage, handling, use and/or disposal of large quantities of perchlorate salts. PMID:19864064

  8. Rapid Ti(III) reduction of perchlorate in the presence of beta-alanine: kinetics, pH effect, complex formation, and beta-alanine effect.

    PubMed

    Wang, Chao; Huang, Zhengdao; Lippincott, Lee; Meng, Xiaoguang

    2010-03-15

    Ti(III) reduction of perchlorate might be a useful method for the treatment of highly perchlorate-contaminated water. Though the reaction rate was usually low, we observed that beta-alanine (HOOCCH(2)CH(2)NH(2)) could significantly promote the reaction. A complete (>99.9%) perchlorate removal was obtained in a solution containing [ClO(4)(-)]=1.0mM, [Ti(III)]=40 mM, and [beta-alanine]=120 mM after 2.5h of reaction under 50 degrees C. The effects of both pH and complex formation on the reaction were then studied. The results showed that without beta-alanine the optimal pH was 2.3. When pH increased from 1.6 to 2.3, the reduction rate increased remarkably. In the pH range >2.3, however, the reduction was significantly inhibited, attributed to the formation of Ti(III) precipitate. The presence of beta-alanine at a molar ratio of [beta-alanine]:[Ti(III)]=3:1 significantly increased the reduction rate of perchlorate even at near neutral pH. This is because beta-alanine formed complexes with Ti(III), which greatly improved the total soluble [Ti(III)] in the pH range between 3.5 and 6. The findings may lead to the development of rapid treatment methods for intermittent and small stream of highly perchlorate-contaminated water, which are resulted from the manufacturing, storage, handling, use and/or disposal of large quantities of perchlorate salts.

  9. Longitudinal compressive failure modes in fiber composites End attachment effects on IITRI type test specimens

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.; Sinclair, J. H.

    1985-01-01

    The end-attachment effects on longitudinal compressive strength of IITRI type specimen unidirectional fiber composites are formally assessed using finite-element analysis (FEA) in conjunction with composite mechanics. Sixteen different cases were analyzed to evaluate end-attachment effects (such as degree of misalignment, type of misalignment, progressive end-tab debonding, and specimen thickness) on stress distribution, peak stresses, buckling loads, and buckling mode shapes. The results obtained from the FEA and comparisons with fractured specimens show that eccentricities induce bending-type stresses which peak near the end-tabs and cause flexural type fracture. Also, guidelines are included for placing back-to-back strain gages to measure the presence/absence of possible end-attachment and eccentricity effects.

  10. Computation of the MHD modes with rotation and kinetic effects: AEGIS

    NASA Astrophysics Data System (ADS)

    Zheng, L.-J.; Kotschenreuther, M.; Turnbull, A.; Waelbroeck, F.; van Dam, J. W.; Berk, H.

    2003-10-01

    A new linear MHD eigenvalue code called AEGIS (Adaptive EiGenfunction Independent Shooting) is being developed at the IFS. The benchmarking of AEGIS with GATO is underway and will be presented. Plasma rotation is being included, with the effect of rotation-enhanced plasma compressibility also taken into account. As a first step in including rotational effects, the ideal MHD model is being employed. Details of the numerical scheme will be described, along with preliminary numerical results. The plan to include kinetic compressiblity will be discussed. With this new code, rotational stabilization of resistive wall modes can be rigorously calculated for the first time. The algorithm also allows FLR effects to be included. Many helpful suggestions from A. Glasser are acknowledged.

  11. Mode shift strategies in intercity transportation and their effect on energy consumption

    NASA Technical Reports Server (NTRS)

    Sokolsky, S.

    1975-01-01

    Policies are examined which, if implemented, could lead to significant energy savings in intercity travel in the northeast corridor arena, without restricting the traveler's freedom of mode choice. The effects on arena energy consumption of introducing new, more energy-efficient aircraft are investigated; and several strategies unrelated to the implementation of new aircraft are introduced to yield reductions in overall intercity energy use. In both parts of this analysis, resulting changes in patronage (modal share) and energy use are demonstrated, leading to new insights into the effectiveness of different potential policies for achieving energy conservation. Some observations on induced demand trends that could be associated with certain strategies and the resultant potential effect on energy conservation are provided.

  12. Nonlinear mode interactions and frequency-jump effects in a doubly tuned oscillator configuration

    NASA Astrophysics Data System (ADS)

    Grun, J.; Lashinsky, H.

    1980-05-01

    Frequency-jump effects associated with nonlinear mode competition are investigated in an oscillator configuration consisting of a passive linear resonance system coupled to an active nonlinear resonance system. These effects give rise to a hysteresis pattern whose height and width can be related to system parameters such as the resonance frequencies, dissipation, coupling coefficient, etc. It is noted that these effects offer a novel means of determining these parameters in cases in which conventional techniques may not be desirable or as advantageous. The analysis provides an qualitative explanation of empirical observations in a recent nuclear magnetic resonance experiment (Timsit and Daniels, 1976). The results also apply to other nonlinear resonance systems such as lasers, microwave generators, and electronic oscillators.

  13. Environmental context effects on episodic memory are dependent on retrieval mode and modulated by neuropsychological status.

    PubMed

    Barak, Ohr; Vakil, Eli; Levy, Daniel A

    2013-01-01

    Contextual change or constancy between occasions of memory formation and retrieval are commonly assumed to affect retrieval success, yet such effects may be inconsistent, and the processes leading to the pattern of effects are still not well understood. We conducted a systematic investigation of environmental context effects on memory, using a range of materials (common objects, pictures of familiar and unfamiliar faces, words, and sentences), and four types of retrieval (free recall, cued recall, recognition, and order memory), all assessed within participants. Additionally, we examined the influence of mnemonic challenge on context effects by examining both healthy participants and a group of patients in rehabilitation following traumatic brain injury (TBI). We found no effects of contextual factors on tests of recognition for either group of participants, but effects did emerge for cued and free recall, with the most prominent effects being on memory for objects. Furthermore, while patients' memory abilities in general were impaired relative to the comparison group, they exhibited greater influences of contextual reinstatement on several recall tasks. These results support suggestions that environmental context effects on memory are dependent on retrieval mode and on the extent to which retrieval is challenging because of neurocognitive status. Additionally, findings of environmental context effects in memory-impaired TBI patients suggest that by harnessing such preserved indirect memory (e.g., using reminder technologies), it may be possible to ameliorate TBI patients' difficulties in explicit remembering. PMID:23480476

  14. Effect of Data Reduction and Fiber-Bridging on Mode I Delamination Characterization of Unidirectional Composites

    NASA Technical Reports Server (NTRS)

    Murri, Gretchen B.

    2011-01-01

    Reliable delamination characterization data for laminated composites are needed for input in analytical models of structures to predict delamination onset and growth. The double-cantilevered beam (DCB) specimen is used to measure fracture toughness, GIc, and strain energy release rate, GImax, for delamination onset and growth in laminated composites under mode I loading. The current study was conducted as part of an ASTM Round Robin activity to evaluate a proposed testing standard for Mode I fatigue delamination propagation. Static and fatigue tests were conducted on specimens of IM7/977-3 and G40-800/5276-1 graphite/epoxies, and S2/5216 glass/epoxy DCB specimens to evaluate the draft standard "Standard Test Method for Mode I Fatigue Delamination Propagation of Unidirectional Fiber-Reinforced Polymer Matrix Composites." Static results were used to generate a delamination resistance curve, GIR, for each material, which was used to determine the effects of fiber-bridging on the delamination growth data. All three materials were tested in fatigue at a cyclic GImax level equal to 90% of the fracture toughness, GIc, to determine the delamination growth rate. Two different data reduction methods, a 2-point and a 7-point fit, were used and the resulting Paris Law equations were compared. Growth rate results were normalized by the delamination resistance curve for each material and compared to the nonnormalized results. Paris Law exponents were found to decrease by 5.4% to 46.2% due to normalizing the growth data. Additional specimens of the IM7/977-3 material were tested at 3 lower cyclic GImax levels to compare the effect of loading level on delamination growth rates. The IM7/977-3 tests were also used to determine the delamination threshold curve for that material. The results show that tests at a range of loading levels are necessary to describe the complete delamination behavior of this material.

  15. Effects of Chromium(VI) and Chromium(III) on Desulfovibrio vulgaris Cells

    SciTech Connect

    M.E. Clark; A. Klonowska; S.B. Thieman; B. Giles; J.D. Wall; and M.W. Fields

    2007-04-19

    cell growth was most likely a consequence of Cr(III), and that an organic ligand could protect D. vulgaris cells from Cr(III) toxicity. Lactate consumption decoupled from sulfate reduction in the presence of Cr(VI) could provide organic carbon for organo- Cr(III) complexes.

  16. Electrophysiological characterization of the class III activity of sotalol and its enantiomers. New interpretation of use-dependent effects.

    PubMed

    Hafner, D; Berger, F; Borchard, U; Kullmann, A; Scherlitz, A

    1988-02-01

    1. Sotalol (Sotalex) and both its optical isomers were studied in electrophysiological experiments with respect to their class III activity of antiarrhythmic drugs. The three substances prolonged action potentials (AP) of guinea-pig papillary muscle and left atrium in concentrations greater than or equal to 3 mumol/l, whereas other AP parameters (resting potential, amplitude and upstroke velocity) remained unchanged. Similar results were observed if papillary muscles were partially depolarized by elevating the extracellular potassium concentration from 4.7 mmol/l to 10-12 mmol/l. 2. The effects of sotalol showed marked frequency dependence (0.017-2 Hz): At slow driving rates sotalol brought about an enhanced AP prolongation as measured by APD30 and APD90. 3. The results were compatible with numerical AP simulation studies on the basis of the assumption that sotalol inhibits time-dependent K-outward current. This leads to the consequence that longer control APs (at low driving rates) are prolonged more effectively by sotalol than shorter ones (at high driving rates). 4. Sotalol effects dynamically followed APD changes due to alterations of driving rate: If APD was decreased under increasing driving frequencies, AP prolongation was diminished. 5. Paired pulse experiments showed that class III activity of sotalol was preserved in premature or delayed single action potentials.

  17. Effect of licorice on the induction of phase II metabolizing enzymes and phase III transporters and its possible mechanism.

    PubMed

    Gong, Hui; Li, Huan-De; Yan, Miao; Zhang, Bi-Kui; Jiang, Pei; Fan, Xin-Rong; Deng, Yang

    2014-12-01

    Licorice has a marked detoxifying effect that can treat drug poisoning and/or relieve adverse effects. However, the exact mechanism of this action is not entirely elucidated, but is believed to be related to the modulation of drug disposition when interacting with other drugs. Additionally, Nuclear factor erythroid 2-related factor 2 (Nrf2) plays a significant role in mediating phase II xenobiotic metabolizing enzymes (XMEs) and phase III transporters. In the present study, we showed that licorice induced the mRNA expression of phase II XMEs UDP-glucuronosyltransferases 1A1 (UGT1A1), glutamate cysteine ligase (GCL), glutathione-s-transferase (GST) and phase III transporters multidrug resistance protein 2 (MRP2), as well as a rapid increase in Nrf2 nuclear accumulation. These findings suggests that licorice may intervene in the Nrf2 signal pathway to induce UGT1A1, GCLC, GST and MRP2, which provide a novel mechanism for the use of licorice to treat drug poisoning and/or relieve adverse effects. PMID:25951662

  18. Risk management for outsourcing biomedical waste disposal – Using the failure mode and effects analysis

    SciTech Connect

    Liao, Ching-Jong; Ho, Chao Chung

    2014-07-15

    Highlights: • This study is based on a real case in hospital in Taiwan. • We use Failure Mode and Effects Analysis (FMEA) as the evaluation method. • We successfully identify the evaluation factors of bio-medical waste disposal risk. - Abstract: Using the failure mode and effects analysis, this study examined biomedical waste companies through risk assessment. Moreover, it evaluated the supervisors of biomedical waste units in hospitals, and factors relating to the outsourcing risk assessment of biomedical waste in hospitals by referring to waste disposal acts. An expert questionnaire survey was conducted on the personnel involved in waste disposal units in hospitals, in order to identify important factors relating to the outsourcing risk of biomedical waste in hospitals. This study calculated the risk priority number (RPN) and selected items with an RPN value higher than 80 for improvement. These items included “availability of freezing devices”, “availability of containers for sharp items”, “disposal frequency”, “disposal volume”, “disposal method”, “vehicles meeting the regulations”, and “declaration of three lists”. This study also aimed to identify important selection factors of biomedical waste disposal companies by hospitals in terms of risk. These findings can serve as references for hospitals in the selection of outsourcing companies for biomedical waste disposal.

  19. Page mode reading with simulated scotomas: a modest effect of interline spacing on reading speed.

    PubMed

    Bernard, Jean-Baptiste; Scherlen, Anne-Catherine; Anne-Catherine, Scherlen; Castet, Eric; Eric, Castet

    2007-12-01

    Crowding is thought to be one potent limiting factor of reading in peripheral vision. While several studies investigated how crowding between horizontally adjacent letters or words can influence eccentric reading, little attention has been paid to the influence of vertically adjacent lines of text. The goal of this study was to examine the dependence of page mode reading performance (speed and accuracy) on interline spacing. A gaze-contingent visual display was used to simulate a visual central scotoma while normally sighted observers read meaningful French sentences following MNREAD principles. The sensitivity of this new material to low-level factors was confirmed by showing strong effects of perceptual learning, print size and scotoma size on reading performance. In contrast, reading speed was only slightly modulated by interline spacing even for the largest range tested: a 26% gain for a 178% increase in spacing. This modest effect sharply contrasts with the dramatic influence of vertical word spacing found in a recent RSVP study. This discrepancy suggests either that vertical crowding is minimized when reading meaningful sentences, or that the interaction between crowding and other factors such as attention and/or visuo-motor control is dependent on the paradigm used to assess reading speed (page vs. RSVP mode).

  20. Effect of Different Groundwater Levels on Seismic Dynamic Response and Failure Mode of Sandy Slope

    PubMed Central

    Huang, Shuai; Lv, Yuejun; Peng, Yanju; Zhang, Lifang; Xiu, Liwei

    2015-01-01

    Heavy seismic damage tends to occur in slopes when groundwater is present. The main objectives of this paper are to determine the dynamic response and failure mode of sandy slope subjected simultaneously to seismic forces and variable groundwater conditions. This paper applies the finite element method, which is a fast and efficient design tool in modern engineering analysis, to evaluate dynamic response of the slope subjected simultaneously to seismic forces and variable groundwater conditions. Shaking table test is conducted to analyze the failure mode and verify the accuracy of the finite element method results. The research results show that dynamic response values of the slope have different variation rules under near and far field earthquakes. And the damage location and pattern of the slope are different in varying groundwater conditions. The destruction starts at the top of the slope when the slope is in no groundwater, which shows that the slope appears obvious whipping effect under the earthquake. The destruction starts at the toe of the slope when the slope is in the high groundwater levels. Meanwhile, the top of the slope shows obvious seismic subsidence phenomenon after earthquake. Furthermore, the existence of the groundwater has a certain effect of damping. PMID:26560103