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Sample records for improved fixed switching

  1. Safe switching from a pdFIX (Immunine®) to a rFIX (Bax326).

    PubMed

    Solano Trujillo, M H; Stasyshyn, O; Rusen, L; Serban, M; Lamas, J L; Perina, F G; Urasinski, T; Oh, M; Knowlton, W B; Valenta-Singer, B; Pavlova, B G; Abbuehl, B

    2014-09-01

    The ability to switch between coagulation factors safely is of common interest to haemophilia patients and treating physicians. This is the first formal prospective comparative evaluation of safety, efficacy and incremental recovery of a plasma-derived FIX (pdFIX) and a recombinant FIX (rFIX) in the same haemophilia B patients following a switch from pdFIX Immunine® to a recently developed rFIX Bax326 product. Patients (aged <65 years) who completed a pretreatment study which prospectively documented the exposure to Immunine® and monitored FIX inhibitors while receiving prophylactic treatment were transitioned into pivotal (patients aged 12-65 years) and paediatric (patients aged <12 years) clinical studies investigating prophylaxis and treatment of bleeding episodes with Bax326. None of the 44 patients developed inhibitory or specific binding anti-FIX antibodies during the course of the studies. A total of 38 unrelated adverse events (AEs) were occurred in 20/44 (45.5%) subjects during the Immunine® study. Following a switch to Bax326, 51 AEs were reported in 25/44 (56.8%) subjects. The incidence of AEs related to Bax326 treatment (two episodes of dysgeusia in one patient) was low (2.3%); there were no serious adverse reactions. The comparison between Immunine® and Bax326 demonstrated analogous haemostatic characteristics and annualized bleeding rates. Overall, there is direct evidence indicating a safe and clinically effective transition from a pdFIX (Immunine®) to a newly developed rFIX (Bax326(1) ) for prophylaxis and treatment of bleeding in previously treated patients of all age cohorts with severe or moderately severe haemophilia B.

  2. Techniques for improved surface discharge switch performance

    SciTech Connect

    Engel, T.G.; Kristiansen, M.; Stemprok, R.

    1995-12-31

    Several techniques have been developed to improve the performance of surface discharge switches (i.e., SDS). These improvements are reported in this investigation and are planned for the development of a prototype switch for the Atlas experimental facility at Los Alamos National Laboratory. One performance improvement technique consists of implanting graphite inserts in the insulator substrate to form capacitively-coupled field emission points with the underlying trigger electrode. These capacitively-coupled field emission points have reduced the trigger risetime normally required for efficient multi-channeling from 1,000 V/ns to 60 V/ns. The resulting discharge has many channels and appears nearly sheet-like in nature. The improved multi-channeling allows the electrodes, which normally rest directly on the insulator surface, to be raised off the insulator surface thereby extending the lifetime of the insulator. Lifetime tests for the improved SDS has been done for 5,000 commutations at 15 kV switch holdoff voltages, 750 kA peak currents, and 70 {micro}s wide pulses. The switch was in good condition at the end of this test and had recorded only 10 prefires during this test. To meet the switch performance requirements for the Atlas facility, further improvements in switch prefire and jitter performance can be accomplished.

  3. Caffeine improves anticipatory processes in task switching.

    PubMed

    Tieges, Zoë; Snel, Jan; Kok, Albert; Wijnen, Jasper G; Lorist, Monicque M; Richard Ridderinkhof, K

    2006-08-01

    We studied the effects of moderate amounts of caffeine on task switching and task maintenance using mixed-task (AABB) blocks, in which participants alternated predictably between two tasks, and single-task (AAAA, BBBB) blocks. Switch costs refer to longer reaction times (RT) on task switch trials (e.g. AB) compared to task-repeat trials (e.g. BB); mixing costs refer to longer RTs in task-repeat trials compared to single-task trials. In a double-blind, within-subjects experiment, two caffeine doses (3 and 5mg/kg body weight) and a placebo were administered to 18 coffee drinkers. Both caffeine doses reduced switch costs compared to placebo. Event-related brain potentials revealed a negative deflection developing within the preparatory interval, which was larger for switch than for repeat trials. Caffeine increased this switch-related difference. These results suggest that coffee consumption improves task-switching performance by enhancing anticipatory processing such as task set updating, presumably through the neurochemical effects of caffeine on the dopamine system.

  4. Efficacy of fixed filtration for rapid kVp-switching dual energy x-ray systems

    SciTech Connect

    Yao, Yuan; Wang, Adam S.; Pelc, Norbert J.

    2014-03-15

    Purpose: Dose efficiency of dual kVp imaging can be improved if the two beams are filtered to remove photons in the common part of their spectra, thereby increasing spectral separation. While there are a number of advantages to rapid kVp-switching for dual energy, it may not be feasible to have two different filters for the two spectra. Therefore, the authors are interested in whether a fixed added filter can improve the dose efficiency of kVp-switching dual energy x-ray systems. Methods: The authors hypothesized that a K-edge filter would provide the energy selectivity needed to remove overlap of the spectra and hence increase the precision of material separation at constant dose. Preliminary simulations were done using calcium and water basis materials and 80 and 140 kVp x-ray spectra. Precision of the decomposition was evaluated based on the propagation of the Poisson noise through the decomposition function. Considering availability and cost, the authors chose a commercial Gd{sub 2}O{sub 2}S screen as the filter for their experimental validation. Experiments were conducted on a table-top system using a phantom with various thicknesses of acrylic and copper and 70 and 125 kVp x-ray spectra. The authors kept the phantom exposure roughly constant with and without filtration by adjusting the tube current. The filtered and unfiltered raw data of both low and high energy were decomposed into basis material and the variance of the decomposition for each thickness pair was calculated. To evaluate the filtration performance, the authors measured the ratio of material decomposition variance with and without filtration. Results: Simulation results show that the ideal filter material depends on the object composition and thickness, and ranges across the lanthanide series, with higher atomic number filters being preferred for more attenuating objects. Variance reduction increases with filter thickness, and substantial reductions (40%) can be achieved with a 2× loss in

  5. Improved techniques for switching power amplifiers

    SciTech Connect

    Flinder, F.M.; Wolfs, P.J.; Kwong, K.C.

    1993-10-01

    The control system design of a dc to 10 kHz bandwidth 45 kVA current sourced power amplifier suitable for geophysical exploration applications is presented. A five-level modulation scheme has been implemented using a modified bridge topology with only four switches. This scheme give as an order of magnitude improvement in switching ripple and control performance over two-level modulation. Using this system, a 50 kHz switch frequency allows a 20 kHz, {minus}3dB bandwidth to be easily achieved. Simulation as well as tenth scale model test results are presented. The current output waveform reproduction is of high quality over the rated dc to 10 kHz frequency range. The THD is 0.3% at 1 kHz.

  6. A novel token protocol in optical burst switch ring network with fixed transmitters and tunable receivers

    NASA Astrophysics Data System (ADS)

    Guo, Xingchen; Wang, Hongxiang; Ji, Yuefeng

    2007-11-01

    Token scheme is one of methods to overcome burst collision problem in Optical Burst Switch Ring Network with Fixed Transmitters and Tunable Receivers, but it brings big End-to-End delay and decreases bandwidth utilization. In this paper a novel token protocol is proposed, which can make better performance on End-to-End delay and bandwidth utilization.

  7. Improved Thermal-Switch Disks Protect Batteries

    NASA Technical Reports Server (NTRS)

    Darcy, Eric; Bragg, Bobby

    1990-01-01

    Improved thermal-switch disks help protect electrical batteries against high currents like those due to short circuits or high demands for power in circuits supplied by batteries. Protects batteries against excessive temperatures. Centered by insulating fiberglass washer. Contains conductive polymer that undergoes abrupt increase in electrical resistance when excessive current raises its temperature above specific point. After cooling, polymer reverts to low resistance. Disks reusable.

  8. Survival and failure modes: platform-switching for internal and external hexagon cemented fixed dental prostheses.

    PubMed

    Anchieta, Rodolfo B; Machado, Lucas S; Hirata, Ronaldo; Coelho, Paulo G; Bonfante, Estevam A

    2016-10-01

    This study evaluated the probability of survival (reliability) of platform-switched fixed dental prostheses (FDPs) cemented on different implant-abutment connection designs. Eighty-four-three-unit FDPs (molar pontic) were cemented on abutments connected to two implants of external or internal hexagon connection. Four groups (n = 21 each) were established: external hexagon connection and regular platform (ERC); external hexagon connection and switched platform (ESC); internal hexagon and regular platform (IRC); and internal hexagon and switched platform (ISC). Prostheses were subjected to step-stress accelerated life testing in water. Weibull curves and probability of survival for a mission of 100,000 cycles at 400 N (two-sided 90% CI) were calculated. The beta values of 0.22, 0.48, 0.50, and 1.25 for groups ERC, ESC, IRC, and ISC, respectively, indicated a limited role of fatigue in damage accumulation, except for group ISC. Survival decreased for both platform-switched groups (ESC: 74%, and ISC: 59%) compared with the regular matching platform counterparts (ERC: 95%, and IRC: 98%). Characteristic strength was higher only for ERC compared with ESC, but not different between internal connections. Failures chiefly involved the abutment screw. Platform switching decreased the probability of survival of FDPs on both external and internal connections. The absence in loss of characteristic strength observed in internal hexagon connections favor their use compared with platform-switched external hexagon connections. © 2016 Eur J Oral Sci.

  9. Consensus analysis of switching multi-agent systems with fixed topology and time-delay

    NASA Astrophysics Data System (ADS)

    Pei, Yongquan; Sun, Jitao

    2016-12-01

    This paper investigates the average consensus problems of the discrete-time Markov switching linear multi-agent systems (LMAS) with fixed topology and time-delay. Firstly, we introduce a concept of the average consensus to adapt the stochastic systems. Secondly, a time-delay switching consensus protocol is proposed. By developing a new signal mode, the switching signal of the systems and the time-delay signal of the controller can be merged into one signal. Thirdly, by Lyapunov technique, two LMIs criteria of average consensus are provided, and they reveal that the consensus of the multi-agent systems relates to the spectral radius of the Laplacian matrix. Furthermore, by our results and CCL-type algorithms, we can get the gain matrices. Finally, a numerical example is given to illustrate the efficiency of our results.

  10. Improved heat switch for gas sorption compressor

    NASA Technical Reports Server (NTRS)

    Chan, C. K.

    1985-01-01

    Thermal conductivities of the charcoal bed and the copper matrix for the gas adsorption compressor were measured by the concentric-cylinder method. The presence of the copper matrix in the charcoal bed enhanced the bed conductance by at least an order of magnitude. Thermal capacities of the adsorbent cell and the heat leaks to two compressor designs were measured by the transient method. The new gas adsorption compressor had a heat switch that could transfer eight times more heat than the previous one. The cycle time for the new prototype compressor is also improved by a factor of eight to within the minute range.

  11. Approximate dynamic programming based solutions for fixed-final-time optimal control and optimal switching

    NASA Astrophysics Data System (ADS)

    Heydari, Ali

    Optimal solutions with neural networks (NN) based on an approximate dynamic programming (ADP) framework for new classes of engineering and non-engineering problems and associated difficulties and challenges are investigated in this dissertation. In the enclosed eight papers, the ADP framework is utilized for solving fixed-final-time problems (also called terminal control problems) and problems with switching nature. An ADP based algorithm is proposed in Paper 1 for solving fixed-final-time problems with soft terminal constraint, in which, a single neural network with a single set of weights is utilized. Paper 2 investigates fixed-final-time problems with hard terminal constraints. The optimality analysis of the ADP based algorithm for fixed-final-time problems is the subject of Paper 3, in which, it is shown that the proposed algorithm leads to the global optimal solution providing certain conditions hold. Afterwards, the developments in Papers 1 to 3 are used to tackle a more challenging class of problems, namely, optimal control of switching systems. This class of problems is divided into problems with fixed mode sequence (Papers 4 and 5) and problems with free mode sequence (Papers 6 and 7). Each of these two classes is further divided into problems with autonomous subsystems (Papers 4 and 6) and problems with controlled subsystems (Papers 5 and 7). Different ADP-based algorithms are developed and proofs of convergence of the proposed iterative algorithms are presented. Moreover, an extension to the developments is provided for online learning of the optimal switching solution for problems with modeling uncertainty in Paper 8. Each of the theoretical developments is numerically analyzed using different real-world or benchmark problems.

  12. Robust consensus tracking control of multiple mechanical systems under fixed and switching interaction topologies

    PubMed Central

    Liu, Jianhui; Zhang, Bin

    2017-01-01

    Consensus tracking problems for multiple mechanical systems are considered in this paper, where information communications are limited between individuals and the desired trajectory is available to only a subset of the mechanical systems. A distributed tracking algorithm based on computed torque approach is proposed in the fixed interaction topology case, in which a robust feedback term is developed for each agent to estimate the external disturbances and the unknown agent dynamics. Then the result is extended to address the case under switching interaction topologies by using Lyapunov approaches and sufficient conditions are given. Two examples and numerical simulations are presented to validate the effectiveness of the proposed robust tracking method. PMID:28542460

  13. Group consensus control for heterogeneous multi-agent systems with fixed and switching topologies

    NASA Astrophysics Data System (ADS)

    Wen, Guoguang; Huang, Jun; Wang, Chunyan; Chen, Zhi; Peng, Zhaoxia

    2016-02-01

    In this paper, the group consensus problems of heterogeneous multi-agent systems with fixed and switching topologies are investigated. First, a class of distributed group consensus protocol is proposed for achieving the group consensus of heterogeneous multi-agent systems by using the neighbours' information. Then, some corresponding sufficient conditions are obtained to guarantee the achievement of group consensus. Rigorous proofs are given by using graph theory, matrix theory and Lyapunov theory. Finally, numerical simulations are also given to verify the theoretical analysis.

  14. An improved, explosively actuated closing switch for pulsed power applications

    SciTech Connect

    Parker, J.V.; Bartsch, R.R.; Cochrane, J.C.; Marsh, S.P.

    1993-01-01

    An improved, explosively actuated closing switch has been developed for the Pegasus II capacitor bank. The new switch design uses an annular metal jet as the switch contact. It has lower resistance and inductance at early time than the original design. A parallel array of 24 switches on Pegasus II has a resistance of less than 10 [mu][Omega] after 300 ns. Measured time behaviors include an intrinsic jitter of 50 ns and a switching delay that depends inversely on the applied voltage.

  15. An improved, explosively actuated closing switch for pulsed power applications

    SciTech Connect

    Parker, J.V.; Bartsch, R.R.; Cochrane, J.C.; Marsh, S.P.

    1993-07-01

    An improved, explosively actuated closing switch has been developed for the Pegasus II capacitor bank. The new switch design uses an annular metal jet as the switch contact. It has lower resistance and inductance at early time than the original design. A parallel array of 24 switches on Pegasus II has a resistance of less than 10 {mu}{Omega} after 300 ns. Measured time behaviors include an intrinsic jitter of 50 ns and a switching delay that depends inversely on the applied voltage.

  16. Backbone switch to abacavir/lamivudine fixed-dose combination: implications for antiretroviral therapy optimization.

    PubMed

    Fantauzzi, Alessandra; Floridia, Marco; Falasca, Francesca; Spanedda, Pierpaolo; Turriziani, Ombretta; Vullo, Vincenzo; Mezzaroma, Ivano

    2015-10-01

    Current guidelines recommend treatment optimization in virologically suppressed patients through switching/ simplification strategies to minimize long-term toxicities and improve adherence. The assessment of inflammation/ coagulation profiles may support therapeutic decisions. We undertook a prospective, non-randomized study to evaluate the efficacy and safety of switching to ABC/3TC from ZDV/3TC or TDF/FTC backbones, in 40 HIV-1 infected patients with HIV-RNA levels <37 copies/mL (>24 months). Main endpoints were viral load levels, CD4+ T cells and toxicities after 48 weeks. Serum inflammation/coagulation markers (ESR, CRP, D-dimer and fibrinogen) and pro-inflammatory cytokines (IL-6, TNF-α, adiponectin, resistin) were evaluated. Baseline characteristics were similar in the two arms, with significantly lower values of e-GFR in patients on TDF/FTC. Markers of inflammation/ coagulation and cytokine profile were also similar, except for higher values of resistin in patients on TDF/ FTC. During follow up, CD4+ T cells increased and viral load remained undetectable in both groups. Patient from ZDV/3TC had significantly greater changes in total cholesterol and serum creatinine. Markers of inflammation/ coagulation remained unchanged. Adiponectin significantly increased in patients from ZDV/3TC. Switching to ABC/3TC was effective and safe. Inflammatory markers remained low in both groups. Some changes in metabolic, kidney and cytokine profiles were apparently specific for baseline cART treatment.

  17. Improved Bearingless Switched-Reluctance Motor

    NASA Technical Reports Server (NTRS)

    Morrison, Carlos R.

    2003-01-01

    The Morrison rotor, named after its inventor, is a hybrid rotor for use in a bearingless switched-reluctance electric motor. The motor is characterized as bearingless in the sense that it does not rely on conventional mechanical bearings: instead, it functions as both a magnetic bearing and a motor. Bearingless switched-reluctance motors are attractive for use in situations in which large variations in temperatures and/or other extreme conditions preclude the use of conventional electric motors and mechanical bearings. In the Morrison motor, as in a prior bearingless switched-reluctance motor, a multipole rotor is simultaneously levitated and rotated. In the prior motor, simultaneous levitation and rotation are achieved by means of two kinds of stator windings: (1) main motor windings and (2) windings that exert levitating forces on a multipole rotor. The multipole geometry is suboptimum for levitation in that it presents a discontinuous surface to the stator pole faces, thereby degrading the vibration-suppression capability of the magnetic bearing. The Morrison rotor simplifies the stator design in that the stator contains only one type of winding. The rotor is a hybrid that includes both (1) a circular lamination stack for levitation and (2) a multipole lamination stack for rotation. A prototype includes six rotor poles and eight stator poles (see figure). During normal operation, two of the four pairs of opposing stator poles (each pair at right angles to the other pair) levitate the rotor. The remaining two pairs of stator poles exert torque on the six-pole rotor lamination stack to produce rotation. The relative lengths of the circular and multipole lamination stacks on the rotor can be chosen to tailor the performance of the motor for a specific application. For a given overall length, increasing the length of the multipole stack relative to the circular stack results in an increase in torque relative to levitation load capacity and stiffness, and vice versa.

  18. Bearingless Switched-Reluctance Motor Improved

    NASA Technical Reports Server (NTRS)

    Morrison, Carlos R.

    2004-01-01

    The Morrison rotor, named after its inventor, is a hybrid rotor for use in a switched reluctance electric motor. The motor is characterized as bearingless in the sense that it does not rely on conventional mechanical bearings: instead, it functions as both a magnetic bearing and a motor. Bearingless switched-reluctance motors are attractive for use in situations in which large variations in temperatures and/or other extreme conditions preclude the use of conventional electric motors and mechanical bearings. In the Morrison motor, as in prior bearingless switched-reluctance motors, a multipole rotor is simultaneously levitated and rotated. In the prior motors, simultaneous levitation and rotation are achieved by means of two kinds of stator windings: (1) main motor windings and (2) windings that exert levitating forces on a multipole rotor. The multipole geometry is suboptimum for levitation because it presents a discontinuous surface to the stator pole faces, thereby degrading the vibration suppression capability of the magnetic bearing. The Morrison rotor simplifies the stator design in that it contains only one type of winding. The rotor is a hybrid that includes both (1) a circular lamination stack for levitation and (2) a multipole lamination stack for rotation. Simultaneous levitation and rotation at 6000 rpm were achieved with a prototype that included six rotor poles and eight stator poles. During normal operation, two of the four pairs of opposing stator poles (each pair at right angles to the other pair) levitate the rotor. The remaining two pairs of stator poles exert torque on the six-pole rotor lamination stack to produce rotation. The relative length of the circular and multipole lamination stacks on the rotor can be chosen to tailor the performance of the motor for a specific application. For a given overall length, increasing the length of the multipole stack relative to the circular stack results in an increase in torque relative to the levitation

  19. Improved Lifetime High Voltage Switch Electrode.

    DTIC Science & Technology

    2014-09-26

    and T.R. Burkes, "Erosion of Spark Gap Electrodes", IEEE Trans. Plasma Sci., PS-8, 149, (1980). 5. L.B. Gordon, M. Kristiansen, M.O. Hagler, H.C...Kirbie, R.M. Ness, L.L. Hatfield and 3.N. Marx, "Material Studies in a High Energy Spark Gap", IEEE Trans. Plasma Sci., PS-10, 286, (1982). 6. A.L...identify by block number) Spark switches, electrodes, ion implantation. _. / 20. ABSTRACT (Cqntnu* on ,.as maide Ii necossery and Identify by block number

  20. Fixed bimonthly aflibercept in naïve and switched neovascular age-related macular degeneration patients: one year outcomes

    PubMed Central

    Warwick, Alasdair N; Leaver, Hannah H; Lotery, Andrew J; Goverdhan, Srini V

    2016-01-01

    AIM To determine real life clinical outcomes in poorly responsive and treatment-naïve neovascular age related macular degeneration (nvAMD) patients using bimonthly fixed dosing aflibercept regimen. METHODS This was a retrospective study of 165 eyes with nvAMD started on aflibercept at Southampton Eye Unit between June 2013 and June 2014. Patients were either switched from pro re nata (PRN) ranibizumab/bevacizumab due to poor response (107 eyes), or treatment-naïve (58 eyes). Patients initially received 3-monthly intravitreal aflibercept injections followed by 2-monthly fixed doses. Clinic visits were scheduled at month 0, 4, 10 and 12. Mean change in best-corrected visual acuity (BCVA) and central retinal thickness (CRT) from baseline were assessed using the Wilcoxon signed-rank test. The proportion of patients maintaining BCVA (<15 letters loss) at 12mo was also evaluated. RESULTS Mean BCVA change at month 12 was +3.29 and +4.67 letters in the switched and naïve aflibercept groups respectively (P<0.01). BCVA was maintained in 95.3% of switched and 96.6% of naïve patients. CRT at month 12 showed a decrease of -6.16 µm in the switched group and -35.36 µm in the naïve group (P<0.01). Patients previously treated with ranibizumab/bevacizumab had on average received 7.4 ranibizumab/bevacizumab injections over 12.6mo, attending 10 clinic visits. The fixed dosing aflibercept regimen required an average of 7.1 injections (naïve group), 7.5 injections (switched group) and 4 clinic visits per year. CONCLUSION Fixed bimonthly aflibercept is effective in both treatment-naïve and poorly responsive nvAMD patients. Adopting a fixed dosing regimen can reduce patient burden without compromising on outcomes. PMID:27588271

  1. Improving the Energy Market: Algorithms, Market Implications, and Transmission Switching

    NASA Astrophysics Data System (ADS)

    Lipka, Paula Ann

    This dissertation aims to improve ISO operations through a better real-time market solution algorithm that directly considers both real and reactive power, finds a feasible Alternating Current Optimal Power Flow solution, and allows for solving transmission switching problems in an AC setting. Most of the IEEE systems do not contain any thermal limits on lines, and the ones that do are often not binding. Chapter 3 modifies the thermal limits for the IEEE systems to create new, interesting test cases. Algorithms created to better solve the power flow problem often solve the IEEE cases without line limits. However, one of the factors that makes the power flow problem hard is thermal limits on the lines. The transmission networks in practice often have transmission lines that become congested, and it is unrealistic to ignore line limits. Modifying the IEEE test cases makes it possible for other researchers to be able to test their algorithms on a setup that is closer to the actual ISO setup. This thesis also examines how to convert limits given on apparent power---as is in the case in the Polish test systems---to limits on current. The main consideration in setting line limits is temperature, which linearly relates to current. Setting limits on real or apparent power is actually a proxy for using the limits on current. Therefore, Chapter 3 shows how to convert back to the best physical representation of line limits. A sequential linearization of the current-voltage formulation of the Alternating Current Optimal Power Flow (ACOPF) problem is used to find an AC-feasible generator dispatch. In this sequential linearization, there are parameters that are set to the previous optimal solution. Additionally, to improve accuracy of the Taylor series approximations that are used, the movement of the voltage is restricted. The movement of the voltage is allowed to be very large at the first iteration and is restricted further on each subsequent iteration, with the restriction

  2. Switching efficiency improvement in spin torque majority gates

    SciTech Connect

    Nikonov, Dmitri E. Manipatruni, Sasikanth; Young, Ian A.

    2014-05-07

    Spin torque majority gate (STMG) is one of the promising options for beyond complementary metal-oxide-semiconductor logic. Improvement of its performance—switching speed vs. required current—is critical for its competitiveness. In this paper, (a) we identify an optimized layout of the gate comprised of thin magnetic wires with in-plane magnetization; (b) we optimize geometries of perpendicular magnetization spin torque majority gates. Micromagnetic simulations demonstrate an improvement in switching current for in-plane magnetization (with less than 1 ns switching time) from 6 mA in the original scheme to 1.5 mA in the present one. Additionally, failures of switching caused by vortex formation are eliminated and desired output magnetization is achieved. Various geometries of STMG with perpendicular magnetization are explored. The scheme with a straight cross proves to be the most advantageous. It is predicted to operate with the switching current of 50 μA and less than 4 ns switching time.

  3. Time-wavelength hybrid optical CDMA system with tunable encoder/decoder using switch and fixed delay-line

    NASA Astrophysics Data System (ADS)

    Min, Seong-Sik; Yoo, Hark; Won, Yong Hyub

    2003-02-01

    A novel tunable encoding/decoding scheme based on an arrayed waveguide grating (AWG) and optical switches for time-wavelength hybrid (TWH) optical code division multiple-access (CDMA) systems is proposed. The scheme uses optical switches and fixed delay lines instead of tunable delay lines (TDLs) and utilizes the structure of the TWH optical signature sequences. The advantages of the scheme are that it can be implemented using fewer elements and that the encoded signal suffers lower loss than in those using TDLs. A TWH optical CDMA system for local area network (LAN) applications using the proposed tunable encoder and a simple fixed decoder is examined and its feasibility is experimentally verified.

  4. Improving quality of life using removable and fixed implant prostheses.

    PubMed

    Pennington, Jeff; Parker, Sid

    2012-04-01

    Removable and fixed implant-retained prostheses can greatly enhance patients' quality of life, improving their speech, appearance, and ability to eat and otherwise function normally. Yet patients may resist this type of treatment due to barriers, including cost, fear, and lengthy treatment times. It is, therefore, important that clinicians engage in discovering and understanding their patients' concerns and expectations in addition to making a thorough and complete diagnosis of their dental conditions. In the case presented, emphasis was placed on patient-clinician communication to correctly facilitate the desired clinical result. The final restoration consisted of a maxillary removable, implant-assisted denture and a mandibular screw-retained, fixed, implant-supported prosthesis.

  5. Consequences of switching from a fixed 2 : 1 ratio of amoxicillin/clavulanate (CLSI) to a fixed concentration of clavulanate (EUCAST) for susceptibility testing of Escherichia coli.

    PubMed

    Leverstein-van Hall, Maurine A; Waar, Karola; Muilwijk, Jan; Cohen Stuart, James

    2013-11-01

    The CLSI recommends a fixed 2 : 1 ratio of co-amoxiclav for broth microdilution susceptibility testing of Enterobacteriaceae, while EUCAST recommends a fixed 2 mg/L clavulanate concentration. The aims of this study were: (i) to determine the influence of a switch from CLSI to EUCAST methodology on Escherichia coli susceptibility rates; (ii) to compare susceptibility results obtained using EUCAST-compliant microdilution with those from disc diffusion and the Etest; and (iii) to evaluate the clinical outcome of patients with E. coli sepsis treated with co-amoxiclav in relation to the susceptibility results obtained using either method. Resistance rates were determined in three laboratories that switched from CLSI to EUCAST cards with the Phoenix system (Becton Dickinson) as well as in 17 laboratories that continued to use CLSI cards with the VITEK 2 system (bioMérieux). In one laboratory, isolates were simultaneously tested by both the Phoenix system and either disc diffusion (n = 471) or the Etest (n = 113). Medical and laboratory records were reviewed for E. coli sepsis patients treated with co-amoxiclav monotherapy. Only laboratories that switched methodology showed an increase in resistance rates - from 19% in 2010 to 31% in 2011 (P < 0.0001). All isolates that tested susceptible by microdilution were also susceptible by disc diffusion or the Etest, but of 326 isolates that tested resistant by microdilution, 43% and 59% tested susceptible by disc diffusion and the Etest, respectively. Among the 89 patients included there was a better correlation between clinical response and measured MICs using the Phoenix system than the Etest. EUCAST methodology resulted in higher co-amoxiclav E. coli resistance rates than CLSI methodology, but correlated better with clinical outcome. EUCAST-compliant microdilution and disc diffusion provided discrepant results.

  6. Economic impact of switching to fixed-dose combination therapy for Japanese hypertensive patients: a retrospective cost analysis

    PubMed Central

    2013-01-01

    Background The prescription of fixed-dose combinations (FDC) of antihypertensive drugs has increased rapidly since the relaxation of the prescription-term restriction. In this study, we used the opportunity of this policy change in Japan as an instrument to assess the causal impact of switching to FDC on hypertensive treatment costs. Methods Claims data from 64 community pharmacies located in Tokyo were used to identify hypertensive patients under continuous treatment with angiotensin-receptor blockers (ARBs). Patients switching to FDC between December 2010 and April 2011 were compared to patients who did not receive FDC (control group). Changes in annual antihypertensive drug costs were compared using a difference-in-differences approach to adjust for patient characteristics and use of concomitant medication. Subpopulation analyses were also performed, taking into account pre-index treatment patterns and prescribers’ characteristics. Results There were 542 patients who switched to FDC and 9664 patients in the control group. No significant differences were observed between the 2 groups, except for antihypertensive drug use patterns before the policy change and prescribers’ characteristics. The switch to FDC was associated with an annual saving of 10,420 yen (US$112.0) in antihypertensive drug costs. Approximately 20% of the FDC patients, however, switched from ARB alone, and their drug costs increased by 2376 yen (US$25.5). Conclusions For hypertensive patients who required ARB-based combination therapy, switching to FDC drugs had a significant cost-saving effect. However, the policy change of relaxing the prescription-term restriction could encourage aggressive treatment, i.e., switching to a combination therapy from monotherapy, regardless of medical conditions. Further research is required to evaluate the possible negative aspects of FDC drugs. PMID:23552327

  7. Maximizing switching current of superconductor nanowires via improved impedance matching

    NASA Astrophysics Data System (ADS)

    Zhang, Labao; Yan, Xiachao; Jia, Xiaoqing; Chen, Jian; Kang, Lin; Wu, Peiheng

    2017-02-01

    The temporary resistance triggered by phase slips will result in the switching of a superconductor nanowire to a permanent normal state, decreasing the switching current. In this letter, we propose an improved impedance matching circuit that releases the transition triggered by phase slips to the load resistor through the radio frequency (RF) port of a bias tee. The transportation properties with different load resistors indicate that the switching current decreases due to the reflection caused by impedance mismatching, and it is maximized by optimized impedance matching. Compared to the same setup without the impedance matching circuit, the switching current was increased from 8.0 μA to 12.2 μA in a niobium nitride nanowire after releasing the temporary transition triggered by phase slips. The leakage process with impedance matching outputs a voltage pulse, which enables the user to directly register the transition triggered by phase slips. The technique for maximizing the switching current has a potential practical application in superconductor devices, and the technique for counting phase slips may be applied to explore the behavior of phase slips.

  8. On Optimal Control of Non-Autonomous Switched Systems with a Fixed Mode Sequence

    NASA Technical Reports Server (NTRS)

    Kamgarpour, Maryam; Tomlin, Claire

    2012-01-01

    We consider differentiability with respect to the switch times of the value function of an optimal control problem for a non-autonomous switched system. The control variables are the switch times between the modes and the input in each mode. We provide a method to compute the derivative of the cost function given a nominal input. Then, we view the optimal control problem as a parametrized optimization problem in which the switch times are the parameters and the optimization is over the set of feasible inputs of each mode. From this point of view, we provide conditions under which the continuity and differentiability of the optimal value function, that is the cost function optimized over the inputs, can be guaranteed.

  9. The signs of ocular-surface disorders after switching from latanoprost to tafluprost/timolol fixed combination: a prospective study

    PubMed Central

    Okumichi, Hideaki; Kiuchi, Yoshiaki; Baba, Tetsuya; Kanamoto, Takashi; Naito, Tomoko; Nakakura, Shunsuke; Tabuchi, Hitoshi; Nii, Hiroki; Sueoka, Chie; Sugimoto, Yosuke

    2017-01-01

    Purpose To evaluate the ocular-surface safety of a 0.001% benzalkonium chloride-containing tafluprost/timolol fixed combination (TTFC) in patients with primary open-angle glaucoma (POAG) or ocular hypertension who have inadequate intraocular pressure (IOP) control with latanoprost monotherapy. Methods This study is a multicenter, prospective, single-arm, open-label clinical study. Patients with POAG or ocular hypertension who have inadequate IOP control with latanoprost monotherapy were considered eligible. After providing informed consent, patients continued latanoprost monotherapy for 12 weeks, followed by a switch to TTFC. We evaluated the extent of ocular-surface damage using superficial punctate keratopathy (SPK) score, tear breakup time (TBUT), hyperemia score, IOP, systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate at 0, 4, and 12 weeks after switching. Results A total of 68 patients were enrolled, of whom, 64 patients were included in the final analysis. No significant changes in SPK score, TBUT, or hyperemia score were observed at 4 and 12 weeks compared with week 0. IOP decreased significantly at 4 (13.9±2.5 mmHg) and 12 (14.1±2.5 mmHg) weeks, relative to week 0 (15.3±2.7 mmHg). No significant changes in either SBP or DBP were observed during the study, although patients’ mean heart rate decreased significantly after switching to TTFC. Adverse drug reactions to TTFC occurred in seven patients including two incidences of asthma and one of arrhythmia, and no events were serious. Conclusion The ocular-surface safety of TTFC is not significantly different to that of latanoprost. Furthermore, switching from latanoprost to TTFC in patients with insufficient IOP control has additive IOP-lowering effects. TTFC is an effective approach for patients receiving latanoprost monotherapy who require more intensive IOP reduction. PMID:28790802

  10. Condition interference in rats performing a choice task with switched variable- and fixed-reward conditions

    PubMed Central

    Funamizu, Akihiro; Ito, Makoto; Doya, Kenji; Kanzaki, Ryohei; Takahashi, Hirokazu

    2015-01-01

    Because humans and animals encounter various situations, the ability to adaptively decide upon responses to any situation is essential. To date, however, decision processes and the underlying neural substrates have been investigated under specific conditions; thus, little is known about how various conditions influence one another in these processes. In this study, we designed a binary choice task with variable- and fixed-reward conditions and investigated neural activities of the prelimbic cortex and dorsomedial striatum in rats. Variable- and fixed-reward conditions induced flexible and inflexible behaviors, respectively; one of the two conditions was randomly assigned in each trial for testing the possibility of condition interference. Rats were successfully conditioned such that they could find the better reward holes of variable-reward-condition and fixed-reward-condition trials. A learning interference model, which updated expected rewards (i.e., values) used in variable-reward-condition trials on the basis of combined experiences of both conditions, better fit choice behaviors than conventional models which updated values in each condition independently. Thus, although rats distinguished the trial condition, they updated values in a condition-interference manner. Our electrophysiological study suggests that this interfering value-updating is mediated by the prelimbic cortex and dorsomedial striatum. First, some prelimbic cortical and striatal neurons represented the action-reward associations irrespective of trial conditions. Second, the striatal neurons kept tracking the values of variable-reward condition even in fixed-reward-condition trials, such that values were possibly interferingly updated even in the fixed-reward condition. PMID:25741231

  11. An improved switching converter model using discrete and average techniques

    NASA Technical Reports Server (NTRS)

    Shortt, D. J.; Lee, F. C.

    1982-01-01

    The nonlinear modeling and analysis of dc-dc converters has been done by averaging and discrete-sampling techniques. The averaging technique is simple, but inaccurate as the modulation frequencies approach the theoretical limit of one-half the switching frequency. The discrete technique is accurate even at high frequencies, but is very complex and cumbersome. An improved model is developed by combining the aforementioned techniques. This new model is easy to implement in circuit and state variable forms and is accurate to the theoretical limit.

  12. Switching from latanoprost to fixed-combination latanoprost-timolol: a 21-day, randomized, double-masked, active-control study in patients with glaucoma and ocular hypertension.

    PubMed

    Olander, Kenneth; Zimmerman, Thom J; Downes, Nina; Schoenfelder, John

    2004-10-01

    Approximately 40% of patients with glaucoma are concomitantly prescribed >or=2 different intraocular pressure (IOP)-lowering medications. An effective and well-tolerated fixed combination of agents requiring once-daily instillation may improve patient compliance. The purpose of this study was to compare the efficacy and safety profile of the fixed combination latanoprost 0.005% + timolol maleate 0.5% QD with those of latanoprost 0.005% monotherapy QD in patients whose elevated IOP (>or=21 mm Hg) was inadequately controlled by latanoprost. This 21-day, randomized, double-masked, active-control study was conducted at 49 study sites in Argentina, Brazil, Colombia, Mexico, Peru, the United States, and Venezuela. Adults with glaucoma or ocular hypertension who had failed to reach an IOP of <21 mm Hg while receiving latanoprost for at least 28 days were enrolled. After an additional 28 days of latanoprost run-in, patients were randomly assigned to continue latanoprost monotherapy or to switch to the fixed combination for 21 days. The intent-to-treat (ITT) population included all patients who received at least 1 dose of double-masked study medication; the per-protocol (PP) analysis included patients who completed the study without a major protocol violation and who had IOP measurements both at baseline and at day 21. The primary end point was the proportion of patients whose IOP was decreased >or=2 mm Hg from the baseline level on day 21. Proportions of patients demonstrating IOP decreases >or=3, >or=4, or >or=5 mm Hg from the baseline level and of patients reaching an 10P fixed combination, n = 175; latanoprost, n = 173; mean [SD] age, 64.4 [13.2] and 63.2 [14.0] years, respectively; 103 women in each group). Baseline demographic and clinical characteristics were similar between groups. A

  13. Effect on intraocular pressure of switching from latanoprost and travoprost monotherapy to timolol fixed combinations in patients with normal-tension glaucoma.

    PubMed

    Igarashi, Ryoko; Togano, Tetsuya; Sakaue, Yuta; Yoshino, Takaiko; Ueda, Jun; Fukuchi, Takeo

    2014-01-01

    Purpose. To evaluate the effect on intraocular pressure (IOP) of switching from latanoprost and travoprost monotherapy to timolol fixed combinations in Japanese patients with normal-tension glaucoma (NTG). Methods. 27 NTG patients (54 eyes) were compared IOP, superficial punctuate keratitis (SPK) scores, and conjunctival injection scores in eyes treated with prostaglandin (PG) or PG analog/beta-blocker (PG/b) fixed-combination 6 months after the change in therapy. Results. The mean baseline intraocular pressure was 17.4 ± 1.59 mmHg in eyes receiving PG therapy only and 17.4 ± 1.69 mmHg in eyes switched to PG/b. Switching to fixed combination therapy from PG monotherapy, the mean IOP was 13.1 ± 1.79 mmHg (P < 0.001)  (-24.71% reduction from baseline) at 6 months. The mean conjunctival injection score was 0.69 for eyes on PG monotherapy and 0.56 for eyes on fixed combination therapy (P = 0.028). The mean SPK scores were 0.46 and 0.53. This difference was not statistically significant (P = 0.463). Conclusions. Switching from PG monotherapy to PG/b fixed combination therapy for NTG resulted in a greater intraocular pressure reduction than PG alone without increasing the number of instillations.

  14. Improving sodium laser guide star brightness by polarization switching

    PubMed Central

    Fan, Tingwei; Zhou, Tianhua; Feng, Yan

    2016-01-01

    Optical pumping with circularly polarized light has been used to enhance the brightness of sodium laser guide star. But the benefit is reduced substantially due to the precession of sodium atoms in geomagnetic field. Switching the laser between left and right circular polarization at the Larmor frequency is proposed to improve the return. With ESO’s laser guide star system at Paranal as example, numerical simulation shows that the return flux is increased when the angle between geomagnetic field and laser beam is larger than 60°, as much as 50% at 90°. The proposal is significant since most astronomical observation is at angle between 60° and 90° and it only requires a minor addition to the delivery optics of present laser system. PMID:26797503

  15. An improved PID switching control strategy for type 1 diabetes.

    PubMed

    Marchetti, Gianni; Barolo, Massimiliano; Jovanovic, Lois; Zisser, Howard; Seborg, Dale E

    2006-01-01

    In order for an "artificial pancreas" to become a reality for ambulatory use, a practical closed-loop control strategy must be developed and critically evaluated. In this paper, an improved PID control strategy for blood glucose control is proposed and evaluated in silico using a physiologic model of Hovorka et al. The key features of the proposed control strategy are: (i) a switching strategy for initiating PID control after a meal and insulin bolus; (ii) a novel time-varying setpoint trajectory, (iii) noise and derivative filters to reduce sensitivity to sensor noise, and (iv) a systematic controller tuning strategy. Simulation results demonstrate that the proposed control strategy compares favorably to alternatives for realistic conditions that include meal challenges, incorrect carbohydrate meal estimates, changes in insulin sensitivity, and measurement noise.

  16. An improved PID switching control strategy for type 1 diabetes.

    PubMed

    Marchetti, Gianni; Barolo, Massimiliano; Jovanovic, Lois; Zisser, Howard; Seborg, Dale E

    2008-03-01

    In order for an "artificial pancreas" to become a reality for ambulatory use, a practical closed-loop control strategy must be developed and validated. In this paper, an improved PID control strategy for blood glucose control is proposed and critically evaluated in silico using a physiologic model of Hovorka et al. [1]. The key features of the proposed control strategy are: 1) a switching strategy for initiating PID control after a meal and insulin bolus; 2) a novel time-varying setpoint trajectory; 3) noise and derivative filters to reduce sensitivity to sensor noise; and 4) a practical controller tuning strategy. Simulation results demonstrate that proposed control strategy compares favorably to alternatives for realistic conditions that include meal challenges, incorrect carbohydrate meal estimates, changes in insulin sensitivity, and measurement noise.

  17. Fixed-dose combination of alogliptin/pioglitazone improves glycemic control in Japanese patients with type 2 diabetes mellitus independent of body mass index

    PubMed Central

    Aoki, Chie; Suzuki, Kunihiro; Kuroda, Hisamoto; Sagara, Masaaki; Shimizu, Masanori; Kasai, Kikuo; Aso, Yoshimasa

    2017-01-01

    ABSTRACT This study investigated the effects of switching from combination therapy with either alogliptin (Alo) or pioglitazone (Pio) to fixed-dose combination therapy (FDCT) with alogliptin and pioglitazone (Alo-Pio FDCT). The usefulness and efficacy of Alo-Pio FDCT were investigated. A total of 50 outpatients with type 2 diabetes mellitus (T2DM) treated with Alo and 47 outpatients with T2DM treated with Pio were switched to Alo-Pio FDCT, and its efficacy and usefulness were evaluated. Significant improvements were observed in hemoglobinA1c (HbA1c), alanine transaminase (ALT), and γ-glutamyl transpeptidase (GGT) levels after switching to Alo-Pio FDCT for 16 weeks in both groups. Only the group switching from Alo to Alo-Pio FDCT showed significant improvements in high-density lipoprotein cholesterol (HDL) levels and triglyceride levels. In a multivariate logistic regression model of the variation in the change of HbA1c at 16 weeks, ALT and GGT were independent predictors of the change of HbA1c at 16 weeks. In addition, the switch to Alo-Pio FDCT improved glycemic control to a certain degree regardless of BMI. Switching from either Alo or Pio to Alo-PIO FDCT may, unlike monotherapy with a DPP-4 inhibitor, be effective for patients with T2DM regardless of whether they are obese or lean. PMID:28303056

  18. Fixed-dose combination of alogliptin/pioglitazone improves glycemic control in Japanese patients with type 2 diabetes mellitus independent of body mass index.

    PubMed

    Aoki, Chie; Suzuki, Kunihiro; Kuroda, Hisamoto; Sagara, Masaaki; Shimizu, Masanori; Kasai, Kikuo; Aso, Yoshimasa

    2017-02-01

    This study investigated the effects of switching from combination therapy with either alogliptin (Alo) or pioglitazone (Pio) to fixed-dose combination therapy (FDCT) with alogliptin and pioglitazone (Alo-Pio FDCT). The usefulness and efficacy of Alo-Pio FDCT were investigated. A total of 50 outpatients with type 2 diabetes mellitus (T2DM) treated with Alo and 47 outpatients with T2DM treated with Pio were switched to Alo-Pio FDCT, and its efficacy and usefulness were evaluated. Significant improvements were observed in hemoglobinA1c (HbA1c), alanine transaminase (ALT), and γ-glutamyl transpeptidase (GGT) levels after switching to Alo-Pio FDCT for 16 weeks in both groups. Only the group switching from Alo to Alo-Pio FDCT showed significant improvements in high-density lipoprotein cholesterol (HDL) levels and triglyceride levels. In a multivariate logistic regression model of the variation in the change of HbA1c at 16 weeks, ALT and GGT were independent predictors of the change of HbA1c at 16 weeks. In addition, the switch to Alo-Pio FDCT improved glycemic control to a certain degree regardless of BMI. Switching from either Alo or Pio to Alo-PIO FDCT may, unlike monotherapy with a DPP-4 inhibitor, be effective for patients with T2DM regardless of whether they are obese or lean.

  19. Improved biocompatibility by postfixation treatment of aldehyde fixed bovine pericardium.

    PubMed

    Moritz, A; Grimm, M; Eybl, E; Grabenwöger, M; Windberger, U; Dock, W; Böck, P; Wolner, E

    1990-01-01

    Long-standing release of locally cytotoxic aldehyde concentrations is responsible for lack of spontaneous endothelialization and increased calcification of glutaraldehyde fixed bovine pericardium. Postfixation treatment with amino acids made in vitro endothelialization of bioprosthetic heart valves possible. Such treated pericardium calcified significantly less (13 +/- 4 micrograms/mg dry weight) than did conventionally processed pericardium (114 +/- 25 micrograms/mg) after 63 days of subcutaneous implantation in rats. To test the ability for spontaneous in vivo endothelialization, 5 sheep had 6 mm grafts made from postfixation treated pericardium (PTP) implanted into the carotid artery, compared to PTFE grafts on the contralateral side, which spontaneously endothelialize in animal models. In a pregnant animal, both grafts occluded. All remaining pericardial grafts remained patent, but one additional PTFE graft occluded and another one was stenosed. The area covered with red thrombus was significantly smaller in the PTP grafts (3.05 +/- 3.9%) than in the PTFE grafts 42 +/- 14% (p = 0.0036); TEM and SEM showed endothelial cells growing directly on the PTP, but only on myofibroblasts in PTFE grafts. Postfixation treatment of glutaraldehyde fixed pericardium aids spontaneous endothelialization and decreases tissue calcification.

  20. Improved apparatus for continuous culture of hydrogen-fixing bacteria

    NASA Technical Reports Server (NTRS)

    Foster, J. F.; Litchfield, J. H.

    1970-01-01

    Improved apparatus permits the continuous culture of Hydrogenomonas eutropha. System incorporates three essential subsystems - /1/ environmentally isolated culture vessel, /2/ analytical system with appropriate sensors and readout devices, /3/ control system with feedback responses to each analytical measurement.

  1. RF MEMS Switches with SiC Microbridges for Improved Reliability

    NASA Technical Reports Server (NTRS)

    Scardelletti, Maximilian C.; Zorman, Christian A.; Oldham, Daniel R.

    2008-01-01

    Radio frequency (RF) microelectromechanical (MEMS) switches offer superior performance when compared to the traditional semiconductor devices such as PIN diodes or GaAs transistors. MEMS switches have a return loss (RL) better than -25 dB, negligible insertion loss (IL), isolation better than -30 dB, and near zero power consumption. However, RF MEMS switches have several drawbacks the most serious being long-term reliability. The ability for the switch to operate for millions or even billions of cycles is a major concern and must be addressed. MEMS switches are basically grouped in two categories, capacitive and metal-to-metal contact. The capacitive type switch consists of a movable metal bridge spanning a fixed electrode and separated by a narrow air gap and thin insulating material. The metal-to-metal contact type utilizes the same basic design but without the insulating material. After prolonged operation the metal bridges, in most of these switches, begin to sag and eventually fail to actuate. For the metal-to-metal type, the two metal layers may actually fuse together. Also if the switches are not packaged properly or protected from the environment moisture may build up and cause stiction between the top and bottom electrodes rendering them useless. Many MEMS switch designs have been developed and most illustrate fairly good RF characteristics. Nevertheless very few have demonstrated both great RF performance and ability to perform millions/billions of switching cycles. Of these, nearly all are of metal-to-metal type so as the frequency increases RF performance decreases.

  2. Development and fabrication of improved power transistor switches

    NASA Technical Reports Server (NTRS)

    Hower, P. L.; Chu, C. K.

    1979-01-01

    A new class of high-voltage power transistors was achieved by adapting present interdigitated thyristor processing techniques to the fabrication of npn Si transistors. Present devices are 2.3 cm in diameter and have V sub CEO (sus) in the range of 400 to 600V. V sub CEO (sus) = 450V devices were made with an (h sub FE)(I sub C) product of 900A at V sub CE = 2.5V. The electrical performance obtained was consistent with the predictions of an optimum design theory specifically developed for power switching transistors. The device design, wafer processing, and assembly techniques are described. Experimental measurements of the dc characteristics, forward SOA, and switching times are included. A new method of characterizing the switching performance of power transistors is proposed.

  3. An improved switching control law for the optimized synchronous electric charge extraction circuit

    NASA Astrophysics Data System (ADS)

    Liu, Weiqun; Badel, Adrien; Formosa, Fabien; Liu, Congzhi; Hu, Guangdi

    2015-12-01

    Nonlinear switching interface circuits are considered as an efficient way to improve the performance of vibration energy harvesters. Among the various approaches, OSECE (Optimized Synchronous Electric Charge Extraction) exhibits satisfying properties: simple switching strategy, good performance in low coupling cases and low load dependency. However, the overdamping induced by the voltage inversion at maximal points leads to performance degeneration in high coupling cases. This paper presents an improved switching control law for the OSECE technique. The new OSECE_PT (OSECE with switching Phase Tuning) technique presented here is to let the switches act ahead or after the maximal point with a phase tuning. Theoretical analysis and numerical simulations show that the OSECE_PT technique can improve the power performance effectively and preserves desired load independence properties.

  4. Switching circuit to improve the frequency modulation difference-intensity THz quantum cascade laser imaging

    SciTech Connect

    Saat, N. K.; Dean, P.; Khanna, S. P.; Salih, M.; Linfield, E. H.; Davies, A. G.

    2015-04-24

    We demonstrate new switching circuit for difference-intensity THz quantum cascade laser (QCL) imaging by amplitude modulation and lock in detection. The switching circuit is designed to improve the frequency modulation so that it can stably lock the amplitude modulation of the QCL and the detector output. The combination of a voltage divider and a buffer in switching circuit to quickly switch the amplitude of the QCL biases of 15.8 V and 17.2 V is successfully to increase the frequency modulation up to ∼100 Hz.

  5. Magnetically operated limit switch has improved reliability, minimizes arcing

    NASA Technical Reports Server (NTRS)

    Steiner, R.

    1966-01-01

    Limit switch for reliable, low-travel, snap action with negligible arcing uses an electrically nonconductive permanent magnet consisting of a ferrimagnetic ceramic and ferromagnetic pole shoes which form a magnetic and electrically conductive circuit with a ferrous-metal armature.

  6. Combined networked switching output feedback control with ?-region stability for performance improvement

    NASA Astrophysics Data System (ADS)

    Nikolakopoulos, George; Dritsas, Leonidas; Delshad, Saleh S.

    2014-06-01

    In this article, a combined networked switching output feedback control scheme, with a ?-region stability performance improvement module is presented. The network induced time delays, that are considered to be time varying and integer multiples of the sampling period, are being embedded in the system model, by state augmentation. The resulting model of the overall networked closed-loop system is switching, with the current measured round-trip time delay acting as the switching rule. Based on this modelling approach, a Linear Matrix Inequality (LMI) tuned switching output feedback controller is designed. The proposed approach establishes robustness against time delays and is able to guarantee the overall stability of the switching closed-loop system. Integrated in the controlled synthesis phase, an LMI tuned performance improvement module is being introduced, based on ?-region stability. Multiple simulation results are being presented that prove the efficacy of the proposed scheme.

  7. High accuracy switched-current circuits using an improved dynamic mirror

    NASA Technical Reports Server (NTRS)

    Zweigle, G.; Fiez, T.

    1991-01-01

    The switched-current technique, a recently developed circuit approach to analog signal processing, has emerged as an alternative/compliment to the well established switched-capacitor circuit technique. High speed switched-current circuits offer potential cost and power savings over slower switched-capacitor circuits. Accuracy improvements are a primary concern at this stage in the development of the switched-current technique. Use of the dynamic current mirror has produced circuits that are insensitive to transistor matching errors. The dynamic current mirror has been limited by other sources of error including clock-feedthrough and voltage transient errors. In this paper we present an improved switched-current building block using the dynamic current mirror. Utilizing current feedback the errors due to current imbalance in the dynamic current mirror are reduced. Simulations indicate that this feedback can reduce total harmonic distortion by as much as 9 dB. Additionally, we have developed a clock-feedthrough reduction scheme for which simulations reveal a potential 10 dB total harmonic distortion improvement. The clock-feedthrough reduction scheme also significantly reduces offset errors and allows for cancellation with a constant current source. Experimental results confirm the simulated improvements.

  8. Formula Switch Leads to Enteral Feeding Tolerance Improvements in Children With Developmental Delays

    PubMed Central

    Minor, Gerard; Ochoa, Juan B.; Storm, Heidi; Periman, Seletha

    2016-01-01

    Background: Children with developmental delays are often dependent on enteral nutrition. The aim of our study was to evaluate improvement in tolerance parameters in these children who were switched from an intact protein formula to a 100% whey, peptide-based formula. Methods: A retrospective chart review of children with developmental delays who were failing to reach adequate nutritional goals on standard polymeric formulas were switched to a 100% whey peptide-based formula. Enteral volume goals, caloric goals, and change in medication used to improve feeding tolerance were assessed before and after formula switch. Results: Medical records of 13 children (aged 8.4 ± 4.6 years) met criteria. All children had a primary diagnosis of developmental delay, and 77% were fed via gastrostomy tube. Of the 13 children assessed, 92% experienced improved feeding tolerance, and 75% of these reported the time to improvement within 1 week after formula switch. Feeding tolerance parameters that improved were vomiting (86%), gagging and retching (75%), high residual volumes (63%), constipation (43%), diarrhea (100%), and poor weight gain (100%). Conclusion: Switching to a 100% whey, peptide-based formula improved symptoms of feeding intolerance in the majority of these developmentally delayed children. PMID:28229094

  9. Glycemic Improvement with a Fixed-dose combination of DPP-4 inhibitor + metformin in patients with Type 2 diabetes (GIFT study).

    PubMed

    Bajaj, Harpreet S; Ye, Chenglin; Jain, Esha; Venn, Karri; Stein, Eden; Aronson, Ronnie

    2017-06-22

    This study investigates changes in A1C following a switch from dual therapy of metformin and DPP-4 inhibitor to a fixed-dose combination (FDC) of metformin + DPP-4 inhibitor following the introduction of the FDC in the provincial formulary. The LMC Diabetes Registry was queried retrospectively for patients with type 2 diabetes, aged between 18 and 80 years with at least one A1C recorded prior and ≥3 months post-switch. Five hundred and sixty-eight subjects with mean age 64 ± 12 years and mean A1C 7.7% ± 1.2% met study criteria. Overall, A1C was 0.3% lower post-switch to FDC (P < .01). In stratified analysis, subjects with baseline A1C between 7% and 10% had 0.4% lower A1C (P < .01), with 31% of these subjects reaching target A1C ≤7%, post-switch. A1C reduction was greater among patients with a higher baseline pill burden: 0.4% among those using ≥10 pills/day vs. 0.1% for those with <10 pills/day (P = .02). In this real-world study, switching to FDC of metformin + DPP-4 inhibitor was associated with a significant improvement in A1C. Switching to FDC, especially in patients with high pill burden, can improve A1C goal achievement in clinical practice. © 2017 John Wiley & Sons Ltd.

  10. Alarm toe switch

    DOEpatents

    Ganyard, Floyd P.

    1982-01-01

    An alarm toe switch inserted within a shoe for energizing an alarm circuit n a covert manner includes an insole mounting pad into which a miniature reed switch is fixedly molded. An elongated slot perpendicular to the reed switch is formed in the bottom surface of the mounting pad. A permanent cylindrical magnet positioned in the forward portion of the slot with a diameter greater than the pad thickness causes a bump above the pad. A foam rubber block is also positioned in the slot rearwardly of the magnet and holds the magnet in normal inoperative relation. A non-magnetic support plate covers the slot and holds the magnet and foam rubber in the slot. The plate minimizes bending and frictional forces to improve movement of the magnet for reliable switch activation. The bump occupies the knuckle space beneath the big toe. When the big toe is scrunched rearwardly the magnet is moved within the slot relative to the reed switch, thus magnetically activating the switch. When toe pressure is released the foam rubber block forces the magnet back into normal inoperative position to deactivate the reed switch. The reed switch is hermetically sealed with the magnet acting through the wall so the switch assembly S is capable of reliable operation even in wet and corrosive environments.

  11. Observational study of patients switched to the fixed travoprost 0.004%/timolol 0.5% combination in Croatia.

    PubMed

    Mandic, Z; Novak-Lauš, K; Bojic, L; Popovic-Suic, S; Maricic-Došen, V; Pelcic, G; Dobutovic, D; Biuk, D; Kovacic, Z; Pavan, J

    2010-10-01

    The purpose of this study was to assess both the benefits of a 3-month travoprost 0.004%/timolol 0.5%fixed combination (trav/tim) regimen in comparison with previous medications for the control of intraocular pressure (IOP) and the tolerability of these drug regimens in glaucoma patients. An observational, non-interventional, open-label study of 406 eyes with primary open angle glaucoma and ocular hypertension was thus undertaken. One drop of trav/tim fixed combination was administered in the evening for 3 months. Patients were divided into five groups according to previous drug regimens: timolol 0.5% monotherapy; betaxolol 0.5% monotherapy; latanoprost 0.005% monotherapy; travoprost 0.004% monotherapy; and dorzolamide 2%/timolol 0.5% fixed combination. Upon medication substitution, the trav/tim fixed combination provided better IOP control and tolerability in all five patient groups. At the 3-month follow up, the mean IOP changes from previous therapy were as follows: 5.2 ± 2.7 mmHg (20.8% change) in timolol 0.5% group; 5.7 ± 2.2 mmHg (22.5% change) in betaxolol 0.5% group; 3.8 ± 2.6 mmHg (24.5% change) in latanoprost 0.005% group; 4.4 ± 2.8 mmHg (20% change) in travoprost 0.004% group; and 3.4 ± 4.1 mmHg (14.5% change) in dorzolamide 2%/timolol 0.5% fixed combination group. The difference between baseline and trav/tim combination patient satisfaction at the 3-month follow-up was significant. Thus, the trav/tim fixed combination provided better IOP control and tolerability than previous mono- or polytherapies. Copyright 2010 Prous Science, S.A.U. or its licensors. All rights reserved.

  12. Fixed dose combination therapy to improve hypertension treatment and control in Latin America.

    PubMed

    González-Gómez, Silvia; Meléndez-Gomez, Mayra Alejandra; López-Jaramillo, Patricio

    2017-07-03

    Hypertension is a major risk factor for cardiovascular disease. Its prevalence is increasing worldwide, and is more common in low and middle-income countries. The effectiveness of hypertension treatment is determined by health cost, awareness, and patients' compliance with the treatment. People worldwide with an adequate control of hypertension correspond to a very small percentage in low and medium income countries as the Latin America ones. Between the causes to explain these are the low availability, affordability and adherence to treatment with multiple pills. It has been proposed that fixed dose combination therapy could improve the availability, affordability, adherence and control of hypertension. This article aims to review the evidence, showing that fixed dose combination can improve adherence, decrease health cost and improve control of hypertension. Improvement in hypertension control with fixed dose combination could make an important contribution to efforts to fight against the global cardiovascular morbidity and mortality. Copyright © 2017 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. All rights reserved.

  13. Improvement on Main/backup Controller Switching Device of the Nozzle Throat Area Control System for a Turbofan Aero Engine

    NASA Astrophysics Data System (ADS)

    Li, Jie; Duan, Minghu; Yan, Maode; Li, Gang; Li, Xiaohui

    2014-06-01

    A full authority digital electronic controller (FADEC) equipped with a full authority hydro-mechanical backup controller (FAHMBC) is adopted as the nozzle throat area control system (NTACS) of a turbofan aero engine. In order to ensure the switching reliability of the main/backup controller, the nozzle throat area control switching valve was improved from three-way convex desktop slide valve to six-way convex desktop slide valve. Simulation results show that, if malfunctions of FAEDC occur and abnormal signals are outputted from FADEC, NTACS will be seriously influenced by the main/backup controller switching in several working states, while NTACS will not be influenced by using the improved nozzle throat area control switching valve, thus the controller switching process will become safer and smoother and the working reliability of this turbofan aero engine is improved by the controller switching device improvement.

  14. Improved glycaemic control by switching from insulin NPH to insulin glargine: a retrospective observational study

    PubMed Central

    Sharplin, Peter; Gordon, Jason; Peters, John R; Tetlow, Anthony P; Longman, Andrea J; McEwan, Philip

    2009-01-01

    Background Insulin glargine (glargine) and insulin NPH (NPH) are two basal insulin treatments. This study investigated the effect on glycaemic control of switching from a NPH-based regimen to a glargine-based regimen in 701 patients with type 1 (n= 304) or type 2 (n= 397) diabetes, using unselected primary care data. Methods Data for this retrospective observational study were extracted from a UK primary care database (The Health Improvement Network). Patients were required to have at least 12 months of data before and after switching from NPH to glargine. The principal analysis was the change in HbA1c after 12 months treatment with glargine; secondary analyses included change in weight and total daily insulin dose. Inconsistent reporting of hypoglycemic episodes precludes reliable reporting of this outcome. Multivariate analyses were used to adjust for baseline characteristics and confounding variables. Results After adjustment, both diabetic cohorts showed statistically significant reductions in mean HbA1c 12 months after the switch, by 0.38% (p < 0.001) in type 1 patients and 0.31% (p < 0.001) in type 2 patients. Improvement in HbA1c was positively correlated with baseline HbA1c; patients with baseline HbA1c ≥ 8% had reductions of 0.57% (p < 0.001) and 0.47% (p < 0.001), respectively. There was no significant change in weight or total daily insulin dose while on glargine. The majority of patients received a basal-bolus regimen prior to and after the switch (mean 79.3% before and 77.2% after switch in type 1 patients, and 80.4% and 76.8%, respectively in type 2 patients, p > 0.05). Conclusion In routine clinical practice, switching from NPH to glargine provides the opportunity for improving glycaemic control in diabetes patients inadequately controlled by NPH. PMID:19152692

  15. A System and Method for Improving the Efficiency and Reliability of a Broadband Transistor Switch for Periodic Switching Applications

    DTIC Science & Technology

    2008-11-03

    34N" substrate. [0017] The properties of NPN and PNP transistors are nearly identical except for the directions of current flow and voltage...periodically driven switch can be used with certain modulator applications. A NPN transistor is provided which switches between an OPEN circuit and a SHORT...configured using only one PNP or NPN transistor with emitter connected to the circuit common ground. A series mode switch is usually configured with one

  16. Exploring new dielectrics to improve switching speeds of carbon nanotube memory devices

    NASA Astrophysics Data System (ADS)

    Lucas, Kristin Anne

    2011-12-01

    The hysteresis in carbon nanotube field effect transistor's (CNTFET) current vs. gate voltage curves can be used for memory devices. Testing possible changes to device structure and design, could improve both their endurance and switching speed characteristics. Preliminary work in the literature shows that the type of dielectric layer is a large factor in the device switching speed. Here, a new dielectric layer and a different device design will be tested to study how they affect the device performance. Results are compared to devices that are commercially available.

  17. An Improved SF6 System for the FXR Induction Linac Blumlein Switches

    SciTech Connect

    DeHope, W; Kihara, R; Griffin, K L; Ong, M; Ross, T

    2007-06-16

    The now-mature FXR (Flash X-Ray) radiographic facility at Lawrence Livermore National Laboratory will be briefly described with emphasis on its pulsed power system. The heart of each accelerating cell's pulse forming Blumlein is it's sulfur hexafluoride-based triggered closing switch. FXR's recent upgrade to a recirculating SF{sub 6} gas reclamation system will be described and the resulting accelerator performance and reliability improvements documented. This was accompanied by a detailed switch breakdown study on FXR's Test Stand and the recent analysis of the resulting statistics will be shown.

  18. Development and fabrication of improved power transistor switches. [fabrication and manufacturing of semiconductor devices

    NASA Technical Reports Server (NTRS)

    Hower, P. L.; Chu, C. K.

    1976-01-01

    A new class of high-voltage power transistors has been achieved by adapting present interdigitated thyristor processing techniques to the fabrication of NPN Si transistors. Present devices are 2.3 cm in diameter. The electrical performance obtained is consistent with the predictions of an optimum design theory specifically developed for power switching transistors. The forward safe operating area of the experimental transistors shows a significant improvement over commercially available devices. The report describes device design, wafer processing, and various measurements which include dc characteristics, forward and reverse second breakdown limits, and switching times.

  19. An improved chemically inducible gene switch that functions in the monocotyledonous plant sugar cane.

    PubMed

    Kinkema, Mark; Geijskes, R Jason; Shand, Kylie; Coleman, Heather D; De Lucca, Paulo C; Palupe, Anthony; Harrison, Mark D; Jepson, Ian; Dale, James L; Sainz, Manuel B

    2014-03-01

    Chemically inducible gene switches can provide precise control over gene expression, enabling more specific analyses of gene function and expanding the plant biotechnology toolkit beyond traditional constitutive expression systems. The alc gene expression system is one of the most promising chemically inducible gene switches in plants because of its potential in both fundamental research and commercial biotechnology applications. However, there are no published reports demonstrating that this versatile gene switch is functional in transgenic monocotyledonous plants, which include some of the most important agricultural crops. We found that the original alc gene switch was ineffective in the monocotyledonous plant sugar cane, and describe a modified alc system that is functional in this globally significant crop. A promoter consisting of tandem copies of the ethanol receptor inverted repeat binding site, in combination with a minimal promoter sequence, was sufficient to give enhanced sensitivity and significantly higher levels of ethanol inducible gene expression. A longer CaMV 35S minimal promoter than was used in the original alc gene switch also substantially improved ethanol inducibility. Treating the roots with ethanol effectively induced the modified alc system in sugar cane leaves and stem, while an aerial spray was relatively ineffective. The extension of this chemically inducible gene expression system to sugar cane opens the door to new opportunities for basic research and crop biotechnology.

  20. Improvement of switching uniformity in Cu/SiO2/Pt resistive memory achieved by voltage prestress

    NASA Astrophysics Data System (ADS)

    Liu, Chih-Yi; Lin, Chao-Han; Liu, Shin-Hung; Bai, Chang-Zong; Zhang, Yu-Xuan

    2015-03-01

    A Cu/SiO2/Pt structure was fabricated to investigate its resistive switching characteristics. The application of DC voltages with different polarities allowed for the reversible manipulation of the structure’s resistance. This resistive switching phenomenon is the result of the formation and rupture of Cu conducting filaments near the Cu/SiO2 interface. However, significant switching dispersion occurred during successive switching cycles, which resulted in operational difficulties and switching failure. In this study, a voltage prestress was applied to the structure in an attempt to minimize the switching dispersion. A statistical technique was used to analyze the status of formation/rupture sites, and a schematic model is proposed to explain the reason for the dispersion improvement. It is suggested that the voltage prestress builds nonconnected filaments and reduces the number of sites of filament formation/rupture. This reduction in the number of sites leads to reduced switching dispersion.

  1. Improved multi-level capability in Si3N4-based resistive switching memory using continuous gradual reset switching

    NASA Astrophysics Data System (ADS)

    Kim, Sungjun; Park, Byung-Gook

    2017-01-01

    In this letter, we compare three different types of reset switching behavior in a bipolar resistive random-access memory (RRAM) system that is housed in a Ni/Si3N4/Si structure. The abrupt, step-like gradual and continuous gradual reset transitions are largely determined by the low-resistance state (LRS). For abrupt reset switching, the large conducting path shows ohmic behavior or has a weak nonlinear current-voltage (I-V) characteristics in the LRS. For gradual switching, including both the step-like and continuous reset types, trap-assisted direct tunneling is dominant in the low-voltage regime, while trap-assisted Fowler-Nordheim tunneling is dominant in the high-voltage regime, thus causing nonlinear I-V characteristics. More importantly, we evaluate the multi-level capabilities of the two different gradual switching types, including both step-like and continuous reset behavior, using identical and incremental voltage conditions. Finer control of the conductance level with good uniformity is achieved in continuous gradual reset switching when compared to that in step-like gradual reset switching. For continuous reset switching, a single conducting path, which initially has a tunneling gap, gradually responds to pulses with even and identical amplitudes, while for step-like reset switching, the multiple conducting paths only respond to incremental pulses to obtain effective multi-level states.

  2. Switching from salmeterol/fluticasone to formoterol/budesonide combinations improves peripheral airway/alveolar inflammation in asthma.

    PubMed

    Akamatsu, Taisuke; Shirai, Toshihiro; Kato, Masato; Yasui, Hideki; Hashimoto, Dai; Fujisawa, Tomoyuki; Tsuchiya, Tomoyoshi; Inui, Naoki; Suda, Takafumi; Chida, Kingo

    2014-02-01

    Combination therapy with an inhaled corticosteroid (ICS) and a long-acting β2-agonist (LABA) in a single inhaler is the mainstay of asthma management. We previously showed that switching from salmeterol/fluticasone combination (SFC) 50/250 μg bid to a fixed-dose formoterol/budesonide combination (FBC) 9/320 μg bid improved asthma control and pulmonary functions, but not fractional exhaled nitric oxide (FeNO), in patients with asthma not adequately controlled under the former treatment regimen. To assess whether switching from SFC to FBC improves peripheral airway/alveolar inflammation in asthma (UMIN000009619). Subjects included 66 patients with mild to moderate asthma receiving SFC 50/250 μg bid for more than 8 weeks. Patients were randomized into FBC 9/320 μg bid or continued the same dose of SFC for 12 weeks. Asthma Control Questionnaire, 5-item version (ACQ5) score, peak expiratory flow, spirometry, FeNO, alveolar NO concentration (CANO), and maximal NO flux in the conductive airways (J'awNO) were measured. Sixty-one patients completed the study. The proportion of patients with an improvement in ACQ5 was significantly higher in the FBC group than in the SFC group (51.6% vs 16.7%, respectively, p = 0.003). A significant decrease in CANO was observed in the FBC group (from 8.8 ± 9.2 ppb to 4.0 ± 2.6 ppb; p = 0.007) compared to the SFC group (from 7.4 ± 7.8 ppb to 6.4 ± 5.0 ppb; p = 0.266) although there was no significant difference in the changes in pulmonary functions between the 2 groups. Similar significant differences were found in the CANO corrected for the axial back diffusion of NO (FBC, from 6.5 ± 8.2 ppb to 2.3 ± 2.5 ppb; and SFC, from 4.3 ± 5.3 ppb to 3.9 ± 4.3 ppb). There was no difference in the changes in FeNO or J'awNO between the 2 groups. Switching therapy from SFC to FBC improves asthma control and peripheral airway/alveolar inflammation even though there is no improvement in pulmonary functions, and FeNO in asthmatic patients

  3. Improved kidney function in patients who switch their protease inhibitor from atazanavir or lopinavir to darunavir

    PubMed Central

    Jose, Sophie; Nelson, Mark; Phillips, Andrew; Chadwick, David; Trevelion, Roy; Jones, Rachael; Williams, Deborah I.; Hamzah, Lisa; Sabin, Caroline A.; Post, Frank A.

    2017-01-01

    Objective: Atazanavir (ATV) and lopinavir (LPV) have been associated with kidney disease progression in HIV positive patients, with no data reported for darunavir (DRV). We examined kidney function in patients who switched their protease inhibitor from ATV or LPV to DRV. Design: Cohort study. Methods: Data were from the UK CHIC study. We compared pre and post switch estimated glomerular filtration rate (eGFR) slopes (expressed in ml/min per 1.73 m2 per year) in all switchers and those with rapid eGFR decline (>5 ml/min per 1.73 m2 per year) on ATV or LPV. Mixed-effects models were adjusted for age, gender, ethnicity, eGFR at switch and time updated CD4+ cell count, HIV RNA and cumulative tenofovir (tenofovir disoproxil fumarate) exposure. Results: Data from 1430 patients were included. At the time of switching to DRV, median age was 45 years, 79% were men, 76% had an undetectable viral load, and median eGFR was 93 ml/min per 1.73 m2. Adjusted mean (95% confidence interval) pre and post switch eGFR slopes were −0.84 (−1.31, −0.36) and 1.23 (0.80, 1.66) for ATV (P < 0.001), and −0.57 (−1.09, −0.05) and 0.62 (0.28, 0.96) for LPV (P < 0.001). Stable or improved renal function was observed in patients with rapid eGFR decline on ATV or LPV who switched to DRV [−15.27 (−19.35, −11.19) and 3.72 (1.78, 5.66), P < 0.001 for ATV, −11.93 (−14.60, −9.26) and 0.87 (−0.54, 2.27), P < 0.001 for LPV]. Similar results were obtained if participants who discontinued tenofovir disoproxil fumarate at the time of switch were excluded. Conclusions: We report improved kidney function in patients who switched from ATV or LPV to DRV, suggesting that DRV may have a more favourable renal safety profile. PMID:28121667

  4. Longevity improvement of optically activated, high gain GaAs photoconductive semiconductor switches

    SciTech Connect

    MAR,ALAN; LOUBRIEL,GUILLERMO M.; ZUTAVERN,FRED J.; O'MALLEY,MARTIN W.; HELGESON,WESLEY D.; BROWN,DARWIN JAMES; HJALMARSON,HAROLD P.; BACA,ALBERT G.

    2000-03-02

    The longevity of high gain GaAs photoconductive semiconductor switches (PCSS) has been extended to over 100 million pulses at 23A, and over 100 pulses at 1kA. This is achieved by improving the ohmic contacts by doping the semi-insulating GaAs underneath the metal, and by achieving a more uniform distribution of contact wear across the entire switch by distributing the trigger light to form multiple filaments. This paper will compare various approaches to doping the contacts, including ion implantation, thermal diffusion, and epitaxial growth. The device characterization also includes examination of the filament behavior using open-shutter, infra-red imaging during high gain switching. These techniques provide information on the filament carrier densities as well as the influence that the different contact structures and trigger light distributions have on the distribution of the current in the devices. This information is guiding the continuing refinement of contact structures and geometries for further improvements in switch longevity.

  5. Nigella sativa fixed and essential oil improves antioxidant status through modulation of antioxidant enzymes and immunity.

    PubMed

    Sultan, Muhammad Tauseef; Butt, Masood Sadiq; Karim, Roselina; Ahmad, Nisar; Ahmad, Rabia Shabbir; Ahmad, Waqas

    2015-03-01

    The onset of 21st century witnessed the awareness among the masses regarding the diet-health linkages. The researchers attempted to explore traditional products/plants were in the domain of pharmacy and nutrition focussing on their health benefits. In the present research intervention, we investigate the role of Nigella sativa fixed oil (NSFO) and essential oil (NSEO) in improving antioxidant status and modulation of enzymes. The National Institute of Health (NIH) provided us 30 Sprague Dawley rats that were equally placed in three groups. The groups were fed on their respective diets (56 days) two experimental diets i.e. D2 (NSFO @ 4.0%) and D3 (NSEO @ 0.30%) and control. The indices pertaining to antioxidant status, antioxidant enzymes, and parameters pertaining to immunity were evaluated at 4 weeks interval. The experimental diets (NSFO@ 4.0% & NSEO@ 0.30%) modulated the activities of antioxidant enzymes i.e., catalase (CAT), superoxide dismutase (SOD), glutathione transferase (GST), glutathione reductase (GR) and glutathione peroxidase (GPx), positively. Indices of antioxidant status like tocopherols and glutathione were in linear relationship with that of GPx, GR and GST (P<0.01). Myeloperoxidase activities were in negative correlation with GST (P<0.01) but positive correlation with some other parameters. In the nutshell, the fixed and essential oil of Nigella sativa are effective in improving the indices pertaining to antioxidant status, however, the immune boosting potential needs further clarification. However, authors are of the view that there is need to explore the molecular targets of Nigella sativa fixed and essential oils. Findings from such studies would be useful to validate this instant study for health promoting potential against diabetes mellitus and cardiovascular disorders.

  6. Improved resistive switching characteristics in Ni/SiNx/p++-Si devices by tuning x

    NASA Astrophysics Data System (ADS)

    Kim, Sungjun; Chang, Yao-Feng; Kim, Min-Hwi; Park, Byung-Gook

    2017-07-01

    This letter studies the effect of the negative-set on the resistive switching performances of CMOS-compatible Ni/SiNx/p++-Si resistive memory devices by simply tuning x. A Ni/SiN1.07/p++-Si device showed lower power switching (20 μW) and better endurance cycles (103) compared to a Ni/SiN0.82/p++-Si device because of the improved negative set behavior and initially lower set and reset currents. In addition, we achieved fast switching speed for set (200 ns) and reset (100 ns) processes in the Ni/SiN1.07/p++-Si device. For the Ni/SiN1.07/p++-Si device, fine adjustment of resistance values is attainable by varying the pulse amplitude and width due to the gradual reset switching characteristics. The barrier-height-dependent conduction model is proposed to explain the change in the current level with the x value.

  7. A low power 12-bit 1 Msps successive approximation register ADC with an improved switching procedure

    NASA Astrophysics Data System (ADS)

    Fubin, Xin; Tao, Yin; Qisong, Wu; Yuanlong, Yang; Fei, Liu; Haigang, Yang

    2015-08-01

    As a key building block of data acquisition systems, power dissipation of the successive approximation register (SAR) ADC determines the total power consumption of the system. In this paper, a low power 12-bit 1 Msps SAR ADC with an improved switching procedure is presented. Power consumption and area occupation could be significantly reduced by using the proposed switching procedure. Compared to converters that use the conventional switching procedure, the average switching energy could be reduced by about 80% and the total capacitance could be reduced by 50%. A simplified digital control logic is utilized to reduce power dissipation and area occupation of the digital control circuits. Simulation results show that the power dissipated by the proposed digital control circuits could be reduced by about 50% compared to the power dissipated by conventional control circuits. The chip has been processed in a standard 0.35 μm CMOS technology and has a core die area of 1.12 mm2. A signal-to-noise-and-distortion-ratio of 64.2 dB has been measured with a 100 kHz signal input under a wide range variation of temperature from -55 to 150 °C. The total power consumption of the prototype is only 0.72 mW with a 3.3 V supply voltage. Project supported by the National Basic Research Program of China (No. 2014CB744600) and the National Natural Science Foundation of China (No. 61474120).

  8. Improvement of patient compliance after switching from conventional neuroleptics to the atypical neuroleptic amisulpride.

    PubMed

    Linden, Michael; Scheel, Tabea; Eich, Franz-Xaver

    2006-11-01

    Medication noncompliance of schizophrenic outpatients is an important problem in clinical practice, causing relapse and illness deterioration. Because atypical neuroleptics have, in controlled clinical studies, been shown to be better tolerated and accepted by patients, the question is whether switching from conventional to atypical neuroleptics such as amisulpride can increase patient compliance also under conditions of routine care. In a drug utilization observation study 570 schizophrenic outpatients, who had been pretreated with conventional neuroleptics and then been switched for individual clinical reasons to amisulpride, were observed for 3 months. Sociodemographic, illness and treatment related variables (e.g. Positive and Negative Symptom Scale, side effects), patients' subjective attitudes, and premedication and treatment compliance were assessed using standardized instruments. A total of 43.7% were rated as being noncompliant with the premedication, while 85.8% were rated as compliant after being switched to amisulpride, including 82.7% of the former noncompliant patients. Patients who had become compliant showed a signicantly better psychopathological status after 3 months as compared to still noncompliant patients, including a lower rate of inpatient stays. Switching noncompliant patients from conventional to atypical neuroleptics like amisulpride can improve patient compliance and psychopathology under conditions of routine treatment.

  9. L-theanine and caffeine improve task switching but not intersensory attention or subjective alertness.

    PubMed

    Einöther, Suzanne J L; Martens, Vanessa E G; Rycroft, Jane A; De Bruin, Eveline A

    2010-04-01

    Tea ingredients L-theanine and caffeine have repeatedly been shown to deliver unique cognitive benefits when consumed in combination. The current randomized, placebo-controlled, double-blind, cross-over study compared a combination of L-theanine (97 mg) and caffeine (40 mg) to a placebo on two attention tasks and a self-report questionnaire before, and 10 and 60 min after consumption. The combination of L-theanine and caffeine significantly improved attention on a switch task as compared to the placebo, while subjective alertness and intersensory attention were not improved significantly. The results support previous evidence that L-theanine and caffeine in combination can improve attention.

  10. An Improved Model Predictive Current Controller of Switched Reluctance Machines Using Time-Multiplexed Current Sensor

    PubMed Central

    Li, Bingchu; Ling, Xiao; Huang, Yixiang; Gong, Liang; Liu, Chengliang

    2017-01-01

    This paper presents a fixed-switching-frequency model predictive current controller using multiplexed current sensor for switched reluctance machine (SRM) drives. The converter was modified to distinguish currents from simultaneously excited phases during the sampling period. The only current sensor installed in the converter was time division multiplexing for phase current sampling. During the commutation stage, the control steps of adjacent phases were shifted so that sampling time was staggered. The maximum and minimum duty ratio of pulse width modulation (PWM) was limited to keep enough sampling time for analog-to-digital (A/D) conversion. Current sensor multiplexing was realized without complex adjustment of either driver circuit nor control algorithms, while it helps to reduce the cost and errors introduced in current sampling due to inconsistency between sensors. The proposed controller is validated by both simulation and experimental results with a 1.5 kW three-phase 12/8 SRM. Satisfied current sampling is received with little difference compared with independent phase current sensors for each phase. The proposed controller tracks the reference current profile as accurately as the model predictive current controller with independent phase current sensors, while having minor tracking errors compared with a hysteresis current controller. PMID:28513554

  11. An Improved Model Predictive Current Controller of Switched Reluctance Machines Using Time-Multiplexed Current Sensor.

    PubMed

    Li, Bingchu; Ling, Xiao; Huang, Yixiang; Gong, Liang; Liu, Chengliang

    2017-05-17

    This paper presents a fixed-switching-frequency model predictive current controller using multiplexed current sensor for switched reluctance machine (SRM) drives. The converter was modified to distinguish currents from simultaneously excited phases during the sampling period. The only current sensor installed in the converter was time division multiplexing for phase current sampling. During the commutation stage, the control steps of adjacent phases were shifted so that sampling time was staggered. The maximum and minimum duty ratio of pulse width modulation (PWM) was limited to keep enough sampling time for analog-to-digital (A/D) conversion. Current sensor multiplexing was realized without complex adjustment of either driver circuit nor control algorithms, while it helps to reduce the cost and errors introduced in current sampling due to inconsistency between sensors. The proposed controller is validated by both simulation and experimental results with a 1.5 kW three-phase 12/8 SRM. Satisfied current sampling is received with little difference compared with independent phase current sensors for each phase. The proposed controller tracks the reference current profile as accurately as the model predictive current controller with independent phase current sensors, while having minor tracking errors compared with a hysteresis current controller.

  12. An improved fixed phased demodulation method combined with phase generated carrier (PGC) and ellipse fitting algorithm

    NASA Astrophysics Data System (ADS)

    Peng, Feng; Hou, Lu; Yang, Jun; Yuan, Yonggui; Li, Chuang; Yan, Dekai; Yuan, Libo; Zheng, Hui; Chang, Zheng; Ma, Kun; Yang, Jiyong

    2015-08-01

    In this paper, we present an improved fixed phased demodulation method combined with phase generated carrier (PGC) and ellipse fitting algorithm (EFA) to enhance the phase resolution and suppress the total harmonic distortion (THD) caused by the laser intensity disturbance (LID) of modulation phase. We make the subtraction operation to the outputs of the two 1×2 couplers to get the differential signals without DC offset, which is used to achieve the fixed phase demodulation. The EFA is applied to construct the standard quadrature signals with the two signals. The last output is utilized to finish the small amplitude (<2π rad) demodulation in PGC method, which can increase the phase resolution. The distortion signals caused by the LID effect can be eliminated by the EFA. According to the result, the phase error of the EFA is 0.03rad, the amplitude error is 5% and the phase resolution of system is 2.0×10-6rad/√Hz@1kHz (-106.3dB) with the THD is 5%.

  13. Dual delta tunnel FET: An energy efficient switch with improved current switching ratio and steeper subthreshold slope

    NASA Astrophysics Data System (ADS)

    Gaurav, Vivek; Dash, Sidhartha; Mishra, Guru Prasad

    2017-07-01

    In this paper, a single gate tunnel FET has been designed with two delta layers in both the source and channel regions. The width, position and doping concentration of both the delta regions are optimized to maximize the current switching ratio. The simulation work of the present DD-TFET device has been carried out by 2-D TCAD device simulator from Synopsys and the results are compared with the results of source delta doped TFET (SD-TFET), channel delta doped TFET (CD-TFET) and conventional TFET. The proposed device exhibits its superiority over other designs in terms of ON-state current, current switching ratio and subthreshold swing. Thus DD-TFET can be used as an energy efficient switch and has the potential to replace MOSFETs in high-speed and low-power applications.

  14. An Improved RD Algorithm for Maneuvering Bistatic Forward-Looking SAR Imaging with a Fixed Transmitter.

    PubMed

    Yuan, Yue; Chen, Si; Zhao, Huichang

    2017-05-19

    In order to improve the azimuth resolution beyond what monostatic synthetic aperture radar (SAR) can achieve in the forward-looking area, an asymmetric configuration bistatic SAR system and its imaging algorithm are proposed in this paper. The transmitter is mounted on a fixed platform in side-looking mode while the receiver moves along a nonlinear trajectory in forward-looking mode. Due to the high velocity and acceleration of the maneuvering platform in both along-track and height direction, the traditional algorithms are no longer applicable. In this paper, a new algorithm based on the high precise 2-D frequency spectrum is proposed, which takes high-order Taylor series expansion terms of the slant range into consideration. The proposed algorithm compensates high-order range-azimuth coupling terms to guarantee the focus accuracy in SAR imaging. The simulation results and error analysis validate the effectiveness of the proposed algorithm and the correctness of our analysis.

  15. Exciter switch

    NASA Technical Reports Server (NTRS)

    Mcpeak, W. L.

    1975-01-01

    A new exciter switch assembly has been installed at the three DSN 64-m deep space stations. This assembly provides for switching Block III and Block IV exciters to either the high-power or 20-kW transmitters in either dual-carrier or single-carrier mode. In the dual-carrier mode, it provides for balancing the two drive signals from a single control panel located in the transmitter local control and remote control consoles. In addition to the improved switching capabilities, extensive monitoring of both the exciter switch assembly and Transmitter Subsystem is provided by the exciter switch monitor and display assemblies.

  16. Self-compliance-improved resistive switching using Ir/TaOx/W cross-point memory

    PubMed Central

    2013-01-01

    Resistive switching properties of a self-compliance resistive random access memory device in cross-point architecture with a simple stack structure of Ir/TaO x /W have been investigated. A transmission electron microscope and atomic force microscope were used to observe the film properties and morphology of the stack. The device has shown excellent switching cycle uniformity with a small operation of ±2.5 V and a resistance ratio of >100. The device requires neither any frorming-process nor current compliance limit for repeatable operation in contrast to conventional resistive random access memory devices. The effect of bottom electrode morphology and surface roughness is also studied. The improvement is due to the enhanced electric field at the nanotips in the bottom electrode and the defective TaO x switching layer which enable controlled filament formation/rupture. The device area dependence of the low resistance state indicates multifilament formation. The device has shown a robust alternating current endurance of >105 cycles and a data retention of >104 s. PMID:24341544

  17. Improvement in Neural Respiratory Drive Estimation From Diaphragm Electromyographic Signals Using Fixed Sample Entropy.

    PubMed

    Estrada, Luis; Torres, Abel; Sarlabous, Leonardo; Jané, Raimon

    2016-03-01

    Diaphragm electromyography is a valuable technique for the recording of electrical activity of the diaphragm. The analysis of diaphragm electromyographic (EMGdi) signal amplitude is an alternative approach for the quantification of the neural respiratory drive (NRD). The EMGdi signal is, however, corrupted by electrocardiographic (ECG) activity, and this presence of cardiac activity can make the EMGdi interpretation more difficult. Traditionally, the EMGdi amplitude has been estimated using the average rectified value (ARV) and the root mean square (RMS). In this study, surface EMGdi signals were analyzed using the fixed sample entropy (fSampEn) algorithm, and compared to the traditional ARV and RMS methods. The fSampEn is calculated using a tolerance value fixed and independent of the standard deviation of the analysis window. Thus, this method quantifies the amplitude of the complex components of stochastic signals (such as EMGdi), and being less affected by changes in amplitude due to less complex components (such as ECG). The proposed method was tested in synthetic and recorded EMGdi signals. fSampEn was less sensitive to the effect of cardiac activity on EMGdi signals with different levels of NRD than ARV and RMS amplitude parameters. The mean and standard deviation of the Pearson's correlation values between inspiratory mouth pressure (an indirect measure of the respiratory muscle activity) and fSampEn, ARV, and RMS parameters, estimated in the recorded EMGdi signal at tidal volume (without inspiratory load), were 0.38±0.12, 0.27±0.11 , and 0.11±0.13, respectively. Whereas at 33 cmH2O (maximum inspiratory load) were 0.83±0.02, 0.76±0.07, and 0.61±0.19 , respectively. Our findings suggest that the proposed method may improve the evaluation of NRD.

  18. Switch from intravenous to subcutaneous immunoglobulin in CIDP and MMN: improved tolerability and patient satisfaction

    PubMed Central

    Marreno, Fabrizio

    2015-01-01

    Objectives: To assess clinical outcomes and patient satisfaction in patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) or multifocal motor neuropathy (MMN) who were switched from intravenous immunoglobulin (IVIG) to subcutaneous immunoglobulin (SCIG). Methods: Eight consecutive patients, four with MMN and four with CIDP, already on long-term, hospital-based IVIG were switched to home-based SCIG. These patients were selected on the basis of their requirement for relatively low treatment doses, problems experienced with IVIG, and their willingness to switch to SCIG. Results: After a mean 33 [standard deviation (SD) 19] months receiving SCIG, 7 patients remained neurologically stable and 6 remained on a similar mean weekly immunoglobulin dose relative to their original intravenous dose. A good outcome was reported by 7 of the 8 patients: there were improvements in nausea and headache (n = 4), need to travel to hospital (n = 4), venous access problems (n = 3), immunoglobulin-induced neutropenia (n = 3), treatment wearing-off fluctuations (n = 2), IVIG-induced allergy requiring antihistamine/hydrocortisone (n = 1) and time taken off work (n = 1). The eighth patient required increasing doses of immunoglobulin to maintain strength but still wanted to continue SCIG. Seven patients completed a questionnaire: there was a very high overall satisfaction level with immunoglobulin treatment [mean 96 (SD 5), visual analogue scale (VAS) where 0 = very unsatisfied, 100 = very satisfied]; and very strong preference for subcutaneous over intravenous immunoglobulin (VAS mean 93 [SD 12] where 0 = prefer IVIG, 100 = prefer SCIG). Conclusions: In seven of the eight patients, SCIG gave improved tolerability and patient satisfaction with similar efficacy compared with IVIG. PMID:25584070

  19. Complete solubilization of formalin-fixed, paraffin-embedded tissue may improve proteomic studies.

    PubMed

    Shi, Shan-Rong; Taylor, Clive R; Fowler, Carol B; Mason, Jeffrey T

    2013-04-01

    Tissue-based proteomic approaches (tissue proteomics) are essential for discovering and evaluating biomarkers for personalized medicine. In any proteomics study, the most critical issue is sample extraction and preparation. This problem is especially difficult when recovering proteins from formalin-fixed, paraffin-embedded (FFPE) tissue sections. However, improving and standardizing protein extraction from FFPE tissue is a critical need because of the millions of archival FFPE tissues available in tissue banks worldwide. Recent progress in the application of heat-induced antigen retrieval principles for protein extraction from FFPE tissue has resulted in a number of published FFPE tissue proteomics studies. However, there is currently no consensus on the optimal protocol for protein extraction from FFPE tissue or accepted standards for quantitative evaluation of the extracts. Standardization is critical to ensure the accurate evaluation of FFPE protein extracts by proteomic methods such as reverse phase protein arrays, which is now in clinical use. In our view, complete solubilization of FFPE tissue samples is the best way to achieve the goal of standardizing the recovery of proteins from FFPE tissues. However, further studies are recommended to develop standardized protein extraction methods to ensure quantitative and qualitative reproducibility in the recovery of proteins from FFPE tissues.

  20. Complete Solubilization of Formalin-Fixed, Paraffin-Embedded Tissue May Improve Proteomic Studies

    PubMed Central

    Shi, Shan-Rong; Taylor, Clive R; Fowler, Carol B; Mason, Jeffrey T

    2013-01-01

    Tissue-based proteomic approaches (tissue proteomics) are essential for discovering and evaluating biomarkers for personalized medicine. In any proteomics study, the most critical issue is sample extraction and preparation. This problem is especially difficult when recovering proteins from formalin-fixed, paraffin-embedded (FFPE) tissue sections. However, improving and standardizing protein extraction from FFPE tissue is a critical need because of the millions of archival FFPE tissues available in tissue banks worldwide. Recent progress in the application of heat-induced antigen retrieval (AR) principles for protein extraction from FFPE tissue has resulted in a number of published FFPE tissue proteomics studies. However, there is currently no consensus on the optimal protocol for protein extraction from FFPE tissue or accepted standards for quantitative evaluation of the extracts. Standardization is critical to ensure the accurate evaluation of FFPE protein extracts by proteomic methods such as reverse phase protein arrays (RPPA), which is now in clinical use. In our view, complete solubilization of FFPE tissue samples is the best way to achieve the goal of standardizing the recovery of proteins from FFPE tissues. However, further studies are recommended to develop standardized protein extraction methods to ensure quantitative and qualitative reproducibility in the recovery of proteins from FFPE tissues. PMID:23339100

  1. A microfabricated fixed path length silicon sample holder improves background subtraction for cryoSAXS.

    PubMed

    Hopkins, Jesse B; Katz, Andrea M; Meisburger, Steve P; Warkentin, Matthew A; Thorne, Robert E; Pollack, Lois

    2015-02-01

    The application of small-angle X-ray scattering (SAXS) for high-throughput characterization of biological macromolecules in solution is limited by radiation damage. By cryocooling samples, radiation damage and required sample volumes can be reduced by orders of magnitude. However, the challenges of reproducibly creating the identically sized vitrified samples necessary for conventional background subtraction limit the widespread adoption of this method. Fixed path length silicon sample holders for cryoSAXS have been microfabricated to address these challenges. They have low background scattering and X-ray absorption, require only 640 nl of sample, and allow reproducible sample cooling. Data collected in the sample holders from a nominal illuminated sample volume of 2.5 nl are reproducible down to q ≃ 0.02 Å(-1), agree with previous cryoSAXS work and are of sufficient quality for reconstructions that match measured crystal structures. These sample holders thus allow faster, more routine cryoSAXS data collection. Additional development is required to reduce sample fracturing and improve data quality at low q.

  2. A microfabricated fixed path length silicon sample holder improves background subtraction for cryoSAXS

    PubMed Central

    Hopkins, Jesse B.; Katz, Andrea M.; Meisburger, Steve P.; Warkentin, Matthew A.; Thorne, Robert E.; Pollack, Lois

    2015-01-01

    The application of small-angle X-ray scattering (SAXS) for high-throughput characterization of biological macromolecules in solution is limited by radiation damage. By cryocooling samples, radiation damage and required sample volumes can be reduced by orders of magnitude. However, the challenges of reproducibly creating the identically sized vitrified samples necessary for conventional background subtraction limit the widespread adoption of this method. Fixed path length silicon sample holders for cryoSAXS have been microfabricated to address these challenges. They have low background scattering and X-ray absorption, require only 640 nl of sample, and allow reproducible sample cooling. Data collected in the sample holders from a nominal illuminated sample volume of 2.5 nl are reproducible down to q ≃ 0.02 Å−1, agree with previous cryoSAXS work and are of sufficient quality for reconstructions that match measured crystal structures. These sample holders thus allow faster, more routine cryoSAXS data collection. Additional development is required to reduce sample fracturing and improve data quality at low q. PMID:26089749

  3. Fatigue Improvement after Switching Multiple Sclerosis Treatment from Interferon-β to Glatiramer Acetate in Clinical Practice.

    PubMed

    Meca-Lallana, José; Hernández, Luis; Caminero, Ana Belén; Girón, Juan Miguel; Cano-Orgaz, Antonio; Carcelén-Gadea, María; Muñoz, Delicias; Durán-Ferreras, Eduardo; Martín-Hernández, Javier; Sánchez-de la Rosa, Rainel

    2016-01-01

    The immunomodulatory effect of glatiramer acetate may help in reducing multiple sclerosis (MS)-related fatigue; however, evidence to prove this notion especially after switching from another immunomodulatory therapy is limited. We assessed the 6-month effect of glatiramer acetate on MS-related fatigue in patients switching from interferon-β (IFN-β) in clinical practice. This was an observational study including 54 patients with relapsing-remitting MS that showed moderate/severe fatigue primarily caused by MS before switching from IFN-β to glatiramer acetate and received glatiramer acetate for ≥6 months in daily practice. Study data were retrospectively collected through chart review at treatment switch and over the following 6 months on glatiramer acetate. Over the 6-month administration of glatiramer acetate, scores on the Modified Fatigue Impact Scale decreased: overall (p < 0.001), physical scale (p < 0.001), cognitive scale (p < 0.001), and psychosocial scale (p < 0.001). The Work Productivity and Activity Impairment Questionnaire showed improvements in work (p = 0.009) and other daily activity impairment (p < 0.001). Health-related quality of life as per the Multiple Sclerosis Impact Scale also improved: physical score (p < 0.001) and psychological score (p < 0.001). Patients with moderate/severe fatigue switching from IFN-β to glatiramer acetate may benefit from fatigue improvements that contribute to reduce their work/activity impairment and improve their quality of life. © 2016 S. Karger AG, Basel.

  4. Latching micro optical switch

    DOEpatents

    Garcia, Ernest J; Polosky, Marc A

    2013-05-21

    An optical switch reliably maintains its on or off state even when subjected to environments where the switch is bumped or otherwise moved. In addition, the optical switch maintains its on or off state indefinitely without requiring external power. External power is used only to transition the switch from one state to the other. The optical switch is configured with a fixed optical fiber and a movable optical fiber. The movable optical fiber is guided by various actuators in conjunction with a latching mechanism that configure the switch in one position that corresponds to the on state and in another position that corresponds to the off state.

  5. Alarm toe switch. [Patent application

    DOEpatents

    Ganyard, F.P.

    1980-11-18

    An alarm toe switch inserted within a shoe for energizing an alarm circuit in a covert manner includes an insole mounting pad into which a miniature reed switch is fixedly molded. An elongated slot perpendicular to the reed switch is formed in the bottom surface of the mounting pad. A permanent cylindrical magnet positioned in the forward portion of the slot with a diameter greater than the pad thickness causes a bump above the pad. A foam rubber block is also positioned in the slot rearwardly of the magnet and holds the magnet in normal inoperative relation. A non-magnetic support plate covers the slot and holds the magnet and foam rubber in the slot. The plate minimizes bending and frictional forces to improve movement of the magnet for reliable switch activation. The bump occupies the knuckle space beneath the big toe. When the big toe is scrunched rearwardly the magnet is moved within the slot relative to the reed switch, thus magnetically activating the switch. When toe pressure is released the foam rubber block forces the magnet back into normal inoperative position to deactivate the reed switch.

  6. Improved nutrition cues switch from efficiency to luxury phenotypes for a long-lived ungulate.

    PubMed

    Michel, Eric S; Flinn, Emily B; Demarais, Stephen; Strickland, Bronson K; Wang, Guiming; Dacus, Chad M

    2016-10-01

    Cervid phenotype can be categorized as efficiency, which promotes survival but not extravagant growth, or luxury which promotes growth of large weaponry and body size. Although nutritional variation greatly influences these phenotypic forms, the potential for subspecies-linked genetic or founder effects from restocking efforts of harvested species has not been eliminated. We measured intergenerational phenotypic change of males in response to improved nutrition in three captive-reared populations of white-tailed deer. Study animals were offspring of females captured from three regions displaying variation in antler and body size as well as nutritional variation. We fed all animals a high-quality diet and measured antler and body size for two generations. We predicted that improved long-term nutrition would cue a switch from efficiency to luxury phenotype for all populations and that regional compensation of antler and body size would occur. Improved nutrition positively influenced all measures of antler and body size; however, changes varied in magnitude. Antler size was more responsive than body size. Improved nutrition also facilitated regional compensation of antler size and partial compensation of body size. Our results show that improved long-term nutrition cues a shift from efficiency to luxury phenotype in a long-lived cervid with weaponry being more responsive than body size. Compensation of antler size suggests that weaponry is greatly influenced by nutrition and is not restricted by subspecies-linked genetic or founder effects from restocking efforts related to our regional populations. Therefore, strategies to improve cervid antler and body size should include habitat management that elevates long-term diet quality.

  7. Improved Hold-Off Characteristics of Gallium Arsenide Photoconductive Switches Used in High Power Applications

    DTIC Science & Technology

    1999-06-01

    that affect the performance of the switches, specifically at high power operation. Surface flashover or the premature breakdown of the PCSS [6] is...Hankla, " Surface flashover for Silicon", SPIE, Vol. 1378 Optically Activated Switches, 217 (1990). [7] N. E. Islam, E. Schamiloglu and C. B...the hold-off characteristics. Opposed contact switches, made from intrinsic GaAs have the characteristics of ’relaxation’ semiconductors . The

  8. Acceleration switch

    DOEpatents

    Abbin, J.P. Jr.; Devaney, H.F.; Hake, L.W.

    1979-08-29

    The disclosure relates to an improved integrating acceleration switch of the type having a mass suspended within a fluid filled chamber, with the motion of the mass initially opposed by a spring and subsequently not so opposed.

  9. Acceleration switch

    DOEpatents

    Abbin, Jr., Joseph P.; Devaney, Howard F.; Hake, Lewis W.

    1982-08-17

    The disclosure relates to an improved integrating acceleration switch of the type having a mass suspended within a fluid filled chamber, with the motion of the mass initially opposed by a spring and subsequently not so opposed.

  10. Coherent switching with decay of mixing: An improved treatment of electronic coherence for non-Born-Oppenheimer trajectories

    NASA Astrophysics Data System (ADS)

    Zhu, Chaoyuan; Nangia, Shikha; Jasper, Ahren W.; Truhlar, Donald G.

    2004-10-01

    The self-consistent decay-of-mixing (SCDM) semiclassical trajectory method for electronically nonadiabatic dynamics is improved by modifying the switching probability that determines the instantaneous electronic state toward which the system decoheres. This method is called coherent switching with decay of mixing (CSDM), and it differs from the previously presented SCDM method in that the electronic amplitudes controlling the switching of the decoherent state are treated fully coherently in the electronic equations of motion for each complete passage through a strong interaction region. It is tested against accurate quantum mechanical calculations for 12 atom-diatom scattering test cases. Also tested are the SCDM method and the trajectory surface hopping method of Parlant and Gislason that requires coherent passages through each strong interaction region, and which we call the "exact complete passage" trajectory surface hopping (ECP-TSH) method. The results are compared with previously presented results for the fewest switches with time uncertainty and Tully's fewest switches (TFS) surface hopping methods and the semiclassical Ehrenfest method. We find that the CSDM method is the most accurate of the semiclassical trajectory methods tested. Including coherent passages improves the accuracy of the SCDM method (i.e., the CSDM method is more accurate than the SCDM method) but not of the trajectory surface hopping method (i.e., the ECP-TSH method is not more accurate on average than the TFS method).

  11. Resistive switching characteristics of Pt/TaOx/HfNx structure and its performance improvement

    NASA Astrophysics Data System (ADS)

    Zhou, Qigang; Zhai, Jiwei

    2013-03-01

    The refractory transition metal nitride (TMN) film Hafnium nitride (HfNx) was successfully prepared on silicon-based substrates as bottom electrodes for resistive random access memory (RRAM) cells in Pt (top)/metal oxide/ HfNx (bottom) sandwich structure. The reproducible resistive switching (RS) characteristics of the memory cells were studied systematically for RRAM applications. The advantages of adopting HfNx instead of Pt as bottom electrode material were demonstrated, including the improvement of the low resistive state value, the RS endurance and the uniformity of RS parameters. The composition and chemical bonding states of the prepared HfNx was analyzed by X-ray photoelectron spectroscopy (XPS) technique. The nitrogen content in the HfNx and the Gibbs free energy of the corresponding metal oxide formation has great influences on the RS properties. The oxygen reservoir ability and diffusion barrier effect of the HfNx play a key role in the RS performance improvement of the RRAM devices.

  12. Improving performance of WDM local packet-switching router with single buffer

    NASA Astrophysics Data System (ADS)

    Wang, Yong; Yin, Hongxi; Xu, Anshi; Wu, Deming

    2000-10-01

    This paper introduces a new structure of WDM local area network. Each node uses WDMA (Wavelength Division Multiplexing Access) to access the network. The switching router of WDM LANs proposed before often use PSC (Passive Star Coupler), but now has been replaced by AWG (Arrayed Waveguide Grating), while each user equipped one tunable transmitter and one tunable receiver is reserved. As we all know, in WDM LAN, destination collision is inevitable when two or more then two nodes want to communicate with the same destination node and this degrades the network performance. So, in all related papers, transmission and receiving procedure must be pre- scheduled in order to preventing from destination collision. However, if there is a configuration, which has the possibility of permitting more than one to access the same destination simultaneously, access scheduling can be more efficient and system performance can be improved. Obviously, adding receiver number or transmitter number is impractical, thus, the only solution is to introduce buffer at the router output side. This is a distinctive difference of the network router we proposed from others. We believe this design can improve the network performance and simulation and numerical results have confirmed that.

  13. Do fixed-dose combination pills or unit-of-use packaging improve adherence? A systematic review.

    PubMed

    Connor, Jennie; Rafter, Natasha; Rodgers, Anthony

    2004-12-01

    Adequate adherence to medication regimens is central to the successful treatment of communicable and noncommunicable disease. Fixed-dose combination pills and unit-of-use packaging are therapy-related interventions that are designed to simplify medication regimens and so potentially improve adherence. We conducted a systematic review of relevant randomized trials in order to quantify the effects of fixed-dose combination pills and unit-of-use packaging, compared with medications as usually presented, in terms of adherence to treatment and improved outcomes. Only 15 trials met the inclusion criteria; fixed-dose combination pills were investigated in three of these, while unit-of-use packaging was studied in 12 trials. The trials involved treatments for communicable diseases (n = 5), blood pressure lowering medications (n = 3), diabetic patients (n = 1), vitamin supplementation (n = 1) and management of multiple medications by the elderly (n = 5). The results of the trials suggested that there were trends towards improved adherence and/or clinical outcomes in all but three of the trials; this reached statistical significance in four out of seven trials reporting a clinically relevant or intermediate end-point, and in seven out of thirteen trials reporting medication adherence. Measures of outcome were, however, heterogeneous, and interpretation was further limited by methodological issues, particularly small sample size, short duration and loss to follow-up. Overall, the evidence suggests that fixed-dose combination pills and unit-of-use packaging are likely to improve adherence in a range of settings, but the limitations of the available evidence means that uncertainty remains about the size of these benefits.

  14. Do fixed-dose combination pills or unit-of-use packaging improve adherence? A systematic review.

    PubMed Central

    Connor, Jennie; Rafter, Natasha; Rodgers, Anthony

    2004-01-01

    Adequate adherence to medication regimens is central to the successful treatment of communicable and noncommunicable disease. Fixed-dose combination pills and unit-of-use packaging are therapy-related interventions that are designed to simplify medication regimens and so potentially improve adherence. We conducted a systematic review of relevant randomized trials in order to quantify the effects of fixed-dose combination pills and unit-of-use packaging, compared with medications as usually presented, in terms of adherence to treatment and improved outcomes. Only 15 trials met the inclusion criteria; fixed-dose combination pills were investigated in three of these, while unit-of-use packaging was studied in 12 trials. The trials involved treatments for communicable diseases (n = 5), blood pressure lowering medications (n = 3), diabetic patients (n = 1), vitamin supplementation (n = 1) and management of multiple medications by the elderly (n = 5). The results of the trials suggested that there were trends towards improved adherence and/or clinical outcomes in all but three of the trials; this reached statistical significance in four out of seven trials reporting a clinically relevant or intermediate end-point, and in seven out of thirteen trials reporting medication adherence. Measures of outcome were, however, heterogeneous, and interpretation was further limited by methodological issues, particularly small sample size, short duration and loss to follow-up. Overall, the evidence suggests that fixed-dose combination pills and unit-of-use packaging are likely to improve adherence in a range of settings, but the limitations of the available evidence means that uncertainty remains about the size of these benefits. PMID:15654408

  15. Improved pyrolysis submodel for the Wen Fixed-Bed Gasifier Program. Final report

    SciTech Connect

    Adesanya, B.A.; Ruffin, Y.

    1991-04-01

    A generalized model for devolatilization of large coal particles typically encountered in a fixed or moving bed gasifier has been developed. Two models were developed, one which does not consider diffusion of the volatile matter from the coal during devolatilization and the other which does consider diffusion of volatile species through the coal matrix. Both models predict a time-temperature history of the particle in a convective heat transfer environment.

  16. Improved pyrolysis submodel for the Wen Fixed-Bed Gasifier Program

    SciTech Connect

    Adesanya, B.A.; Ruffin, Y.

    1991-04-01

    A generalized model for devolatilization of large coal particles typically encountered in a fixed or moving bed gasifier has been developed. Two models were developed, one which does not consider diffusion of the volatile matter from the coal during devolatilization and the other which does consider diffusion of volatile species through the coal matrix. Both models predict a time-temperature history of the particle in a convective heat transfer environment.

  17. Switching the nucleoside reverse transcriptase inhibitor backbone to tenofovir disoproxil fumarate + emtricitabine promptly improves triglycerides and low-density lipoprotein cholesterol in dyslipidaemic patients.

    PubMed

    Valantin, M A; Bittar, R; de Truchis, P; Bollens, D; Slama, L; Giral, P; Bonnefont-Rousselot, D; Pétour, P; Aubron-Olivier, C; Costagliola, D; Katlama, C

    2010-03-01

    To assess the impact of switching to tenofovir disoproxil fumarate + emtricitabine on lipid parameters. HIV-infected patients with plasma viral load <400 copies/mL, fasted triglycerides from 2.3 to 11.4 mmol/L and/or fasted low-density lipoprotein (LDL)-cholesterol >4.1 mmol/L were randomized to switch the nucleoside reverse transcriptase inhibitor (NRTI) backbone to fixed-dose combination tenofovir disoproxil fumarate + emtricitabine or to maintain the baseline antiretroviral regimen (the control group). The study has been registered with ClinicalTrials.gov under the identifier NCT00323492. Ninety-one patients were included in the intent-to-treat (ITT) analysis with triglycerides 2.4 mmol/L and LDL-cholesterol 4.0 mmol/L (median values). At week 12, the median changes from baseline of triglycerides were -0.5 mmol/L (-25%; n = 46) and -0.1 mmol/L (-6%; n = 45) in the tenofovir disoproxil fumarate + emtricitabine and control groups, respectively, indicating a difference of -0.4 mmol/L (P = 0.034) [95% confidence interval (CI): -0.9 to -0.0]. Similarly for LDL-cholesterol, changes of -0.4 mmol/L (-9%) and -0.1 mmol/L (-1%) were observed in the tenofovir disoproxil fumarate + emtricitabine and control groups, respectively, indicating a difference of -0.4 mmol/L (P = 0.031) [95% CI: -0.7 to -0.0]. The proportion of patients with LDL-cholesterol >4.1 mmol/L decreased from 48% at baseline to 26% at week 12 in the tenofovir disoproxil fumarate + emtricitabine group versus no change in the control group. No virological failure was observed during the study. Switching to tenofovir disoproxil fumarate + emtricitabine in dyslipidaemic HIV-infected patients improves triglycerides and LDL-cholesterol.

  18. Improved RDX detoxification with starch addition using a novel nitrogen-fixing aerobic microbial consortium from soil contaminated with explosives.

    PubMed

    Khan, Muhammad Imran; Yang, Jihoon; Yoo, Byungun; Park, Joonhong

    2015-04-28

    In this work, we developed and characterized a novel nitrogen-fixing aerobic microbial consortium for the complete detoxification of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). Aerobic RDX biodegradation coupled with microbial growth and nitrogen fixation activity were effectively stimulated by the co-addition of starch and RDX under nitrogen limiting conditions. In the starch-stimulated nitrogen-fixing RDX degradative consortium, the RDX degradation activity was correlated with the xplA and nifH gene copy numbers, suggesting the involvement of nitrogen fixing populations in RDX biodegradation. Formate, nitrite, nitrate, and ammonia were detected as aerobic RDX degradation intermediates without the accumulation of any nitroso-derivatives or NDAB (4-nitro-2,4-diazabutanal), indicating nearly complete mineralization. Pyrosequencing targeting the bacterial 16S rRNA genes revealed that the Rhizobium, Rhizobacter and Terrimonas population increased as the RDX degradation activity increased, suggesting their involvement in the degradation process. These findings imply that the nitrogen-fixing aerobic RDX degrading consortium is a valuable microbial resource for improving the detoxification of RDX-contaminated soil or groundwater, especially when combined with rhizoremediation. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Improved silica-PLC Mach-Zehnder interferometer type optical switches with error dependence compensation of directional coupler

    NASA Astrophysics Data System (ADS)

    Wang, Jun; Yi, Jia; Guo, Lijun; Liu, Peng; Hall, Trevor J.; Sun, DeGui

    2017-03-01

    For the most popular structure of planer lightwave circuit (PLC) 2×2 thermo-optic switches, Mach-Zehnder interferometer (MZI), a full range of splitting ratio errors of directional coupler (DC) are investigated. All the parameters determining the splitting ratio are the dimensions and the refractive indices of the waveguide core and cladding layers. In this work, the coherent relationships between the waveguide size and the refractive indices are analyzed and then the error compensation between the width and the refractive index of waveguide core, and the controllable effect of over clad layer refractive index error upon the MZI-type optical switch are all discovered with numerical calculation and BPM simulations. Then, an MZI-type 2×2 thermo-optic switch having a higher error tolerance is established with the efficient optimizations of all the 3 dB-DC parameters. As a result, for the symmetric MZI switch, an insertion loss of 1.5 dB and optical extinction ratio of over 20 dB are realized for the average tolerance of±5.0%. An asymmetric arm optical phase and unequal arm lengths is also employed to improve the uniformities of insertion loss. The agreements between the designs and the experiments are recognized, leading to a wide adoption of practical silica-PLC optical switch products.

  20. Improvement in health-related quality of life in patients with haemophilia B treated with nonacog beta pegol, a new extended half-life recombinant FIX product.

    PubMed

    Chowdary, P; Kearney, S; Regnault, A; Hoxer, C S; Yee, D L

    2016-07-01

    Health-related quality of life (HRQoL) of individuals with haemophilia has greatly improved with the use of factor replacement and routine prophylaxis. To explore the HRQoL of individuals with haemophilia B treated with nonacog beta pegol, an extended half-life recombinant factor IX, in a single-blind, randomized multinational phase III pivotal trial (paradigm(™) 2) and its open-label extension (paradigm(™) 4). In the pivotal trial, adolescents and adults with haemophilia B were allocated to 28-week on-demand treatment or randomized to 52 weeks of prophylaxis with 10 or 40 IU kg(-1) nonacog beta pegol administered every seven days. In the extension trial, patients could continue on the same treatment or switch to the alternate dosing regimen at any time. HRQoL was assessed with the HAEMO-QOL/HAEM-A-QOL age-specific questionnaires and the EQ-5D. In the pivotal trial, adults receiving 40 IU kg(-1) prophylaxis reported significant improvements in the 'HAEM-A-QOL Total' score (-6.4 ± 8.5, P = 0.017) and in 'Sport' (-15.3 ± 8.5, P = 0.020), 'Feeling' (-15.2 ± 18.3, P = 0.010) and 'Partnership' (-9.6 ± 15.5, P = 0.046) domain scores; no significant improvements were seen in the other arms. At the pivotal trial end, fewer patients reported problems in the EQ-5D 'Mobility' and 'Pain/Discomfort' dimensions, in particular those receiving prophylaxis. In the extension trial, adult patients switching from 10 to 40 IU kg(-1) prophylaxis showed significant improvements in 'HAEM-A-QOL Total' score (-12.5 ± 8.7, P = 0.016) and 'Physical health' domain (-23.1 ± 14.4, P = 0.016). Prophylactic treatment with nonacog beta pegol 40 IU kg(-1) once weekly leads to HRQoL benefits in individuals with haemophilia B; this might be related to fewer bleeding episodes and higher FIX activity levels. © 2016 John Wiley & Sons Ltd.

  1. Improvement of the noise figure of the CEBAF switched electrode electronics BPM system

    NASA Astrophysics Data System (ADS)

    Powers, Tom

    1998-12-01

    The Continuous Electron Beam Accelerator Facility (CEBAF) is a high-intensity continuous wave electron accelerator for nuclear physics located at Thomas Jefferson National Accelerator Facility. A beam energy of 4 GeV is achieved by recirculating the electron beam five times through two anti-parallel 400 MeV linacs. In the linacs, where there is recirculated beam, the BPM specifications must be met for beam intensities between 1 and 100 μA. In the transport lines the BPM specifications must be met for beam intensities between 100 nA and 200 μA. To avoid a complete redesign of the existing electronics, we investigated ways to improve the noise figure of the linac BPM switched-electrode electronics (SEE) so that they could be used in the transport lines. We found that the out-of-band noise contributed significantly to the overall system noise figure. This paper will focus on the source of the excessive out-of-band noise and how it was reduced. The development, commissioning and operational results of this low noise variant of the linac style SEE BPMs as well as techniques for determining the noise figure of the rf chain will also be presented.

  2. Age Differences in the Transfer and Maintenance of Practice-Induced Improvements in Task Switching: The Impact of Working-Memory and Inhibition Demands

    PubMed Central

    Kray, Jutta; Fehér, Balázs

    2017-01-01

    Recent aging studies on training in task switching found that older adults showed larger improvements to an untrained switching task as younger adults do. However, less clear is what type of cognitive control processes can explain these training gains as participants were trained with a particular type of switching task including bivalent stimuli, requiring high inhibition demands, and no task cues helping them keeping track of the task sequence, and by this, requiring high working-memory (WM) demands. The aims of this study were first to specify whether inhibition, WM, or switching demands are critical for the occurrence of transfer and whether this transfer depends on the degree of overlap between training and transfer situation; and second to assess whether practiced-induced gains in task switching can be maintained over a longer period of time. To this end, we created five training conditions that varied in switching (switching vs. single task training), inhibition (switching training with bivalent or univalent stimuli), and WM demands (switching training with or without task cues). We investigated 81 younger adults and 82 older adults with a pretest-training-posttest design and a follow-up measurement after 6 months. Results indicated that all training and age groups showed improvements in task switching and a differential effect of training condition on improvements to an untrained switching task in younger and older adults. For younger adults, we found larger improvements in task switching for the switching groups than the single-task training group independently of inhibition and WM demands, suggesting that practice in switching is most critical. However, these benefits disappeared after 6 months. In contrast, for older adults training groups practicing task switching under high inhibition demands showed larger improvements to untrained switching tasks than the other groups. Moreover, these benefits were maintained over time. We also found that the transfer

  3. Age Differences in the Transfer and Maintenance of Practice-Induced Improvements in Task Switching: The Impact of Working-Memory and Inhibition Demands.

    PubMed

    Kray, Jutta; Fehér, Balázs

    2017-01-01

    Recent aging studies on training in task switching found that older adults showed larger improvements to an untrained switching task as younger adults do. However, less clear is what type of cognitive control processes can explain these training gains as participants were trained with a particular type of switching task including bivalent stimuli, requiring high inhibition demands, and no task cues helping them keeping track of the task sequence, and by this, requiring high working-memory (WM) demands. The aims of this study were first to specify whether inhibition, WM, or switching demands are critical for the occurrence of transfer and whether this transfer depends on the degree of overlap between training and transfer situation; and second to assess whether practiced-induced gains in task switching can be maintained over a longer period of time. To this end, we created five training conditions that varied in switching (switching vs. single task training), inhibition (switching training with bivalent or univalent stimuli), and WM demands (switching training with or without task cues). We investigated 81 younger adults and 82 older adults with a pretest-training-posttest design and a follow-up measurement after 6 months. Results indicated that all training and age groups showed improvements in task switching and a differential effect of training condition on improvements to an untrained switching task in younger and older adults. For younger adults, we found larger improvements in task switching for the switching groups than the single-task training group independently of inhibition and WM demands, suggesting that practice in switching is most critical. However, these benefits disappeared after 6 months. In contrast, for older adults training groups practicing task switching under high inhibition demands showed larger improvements to untrained switching tasks than the other groups. Moreover, these benefits were maintained over time. We also found that the transfer

  4. Dry Block Calibrator with Improved Temperature Field and Integrated Fixed-Point Cells

    NASA Astrophysics Data System (ADS)

    Hohmann, Michael; Marin, Sebastian; Schalles, Marc; Fröhlich, Thomas

    2017-02-01

    To reduce uncertainty of calibrations of contact thermometers using dry block calibrators, a concept was developed at Institute for Process Measurement and Sensor Technology of Technische Universität Ilmenau. This concept uses a multi-zone heating, heat flux sensors and a multiple fixed-point cell. The paper shows the concept and its validation on the basis of a dry block calibrator with a working temperature range of 70°C to 430°C. The experimental results show a stability of ± 4 mK for the reference temperature and axial temperature differences in the normalization block less than ± 55 mK.

  5. UV-fixed-thick-blotch preparation improves sensitivity of auramine staining.

    PubMed

    Cejudo-García, M A; Munoz-Davila, M J; Martinez-Lirola, M J

    2013-10-01

    We describe here a very simple modification of the auramine staining procedure based on preparation of a UV-fixed thick blotch which allowed us to reach an overall sensitivity of 0.82 (592 acid-fast bacillus [AFB]-positive specimens/722 initial respiratory specimens with positive mycobacterial culture) and sensitivities of 0.93 (526 AFB-positive specimens/564 culture-positive specimens) for Mycobacterium tuberculosis complex and 0.42 (66 AFB-positive specimens/158 culture-positive specimens) for nontuberculous mycobacteria.

  6. Improved Alkane Production in Nitrogen-Fixing and Halotolerant Cyanobacteria via Abiotic Stresses and Genetic Manipulation of Alkane Synthetic Genes.

    PubMed

    Kageyama, Hakuto; Waditee-Sirisattha, Rungaroon; Sirisattha, Sophon; Tanaka, Yoshito; Mahakhant, Aparat; Takabe, Teruhiro

    2015-07-01

    Cyanobacteria possess the unique capacity to produce alkane. In this study, effects of nitrogen deficiency and salt stress on biosynthesis of alkanes were investigated in three kinds of cyanobacteria. Intracellular alkane accumulation was increased in nitrogen-fixing cyanobacterium Anabaena sp. PCC7120, but decreased in non-diazotrophic cyanobacterium Synechococcus elongatus PCC7942 and constant in a halotolerant cyanobacterium Aphanothece halophytica under nitrogen-deficient condition. We also found that salt stress increased alkane accumulation in Anabaena sp. PCC7120 and A. halophytica. The expression levels of two alkane synthetic genes were not upregulated significantly under nitrogen deficiency or salt stress in Anabaena sp. PCC7120. The transformant Anabaena sp. PCC7120 cells with additional alkane synthetic gene set from A. halophytica increased intracellular alkane accumulation level compared to control cells. These results provide a prospect to improve bioproduction of alkanes in nitrogen-fixing halotolerant cyanobacteria via abiotic stresses and genetic engineering.

  7. Quick fixes to improve workers’ health: Results using engineering assessment technology

    PubMed Central

    Haas, E.J.; Cecala, A.B.

    2017-01-01

    Personal respirable dust sampling and the evaluation of control technologies have been providing exposure information to the mining industry but not necessarily in a way that shows how technology can be integrated to provide organizational support and resources for workers to mitigate dust sources on site. In response, the U.S. National Institute for Occupational Safety and Health (NIOSH) used previously developed Helmet-CAM technology to design and engage in a behavioral/engineering cooperative intervention to initiate and enhance mine site conversations about the risks and potential occurrences of respirable silica dust exposures on the job as well as provide impetus and solutions for mitigating higher sources of dust. The study involved 48 workers from five mine sites, who agreed to participate between April 2015 and September 2016. Using the Helmet-CAM in this series of longitudinal interventions revealed several exposure trends in respirable silica dust sources and, in many cases, simple quick-fix strategies to reduce their sources. This paper focuses on several specific identified sources of dust that were elevated but could be reduced through basic engineering fixes, low-cost resources, and supportive communication from management to remind and engage workers in protective work practices. PMID:28867831

  8. Short pulsed gain-switched fiber laser with improved efficiency utilizing unabsorbed pump recovery.

    PubMed

    Petelin, Jaka; Agrež, Vid; Podobnik, Boštjan; Petkovšek, Rok

    2014-08-25

    A simple solution for increasing the slope efficiency of a gain-switched fiber laser based on Yb-doped active fiber is presented. By adding a fiber amplifier stage, which recovers the unabsorbed pump light from the gain-switched oscillator, a significant increase in slope efficiency is achieved. The pulses at 1030-nm wavelength have an FWHM of 28 ns and a peak power of 2.3 kW.

  9. Superior bit error rate and jitter due to improved switching field distribution in exchange spring magnetic recording media.

    PubMed

    Suess, D; Fuger, M; Abert, C; Bruckner, F; Vogler, C

    2016-06-01

    We report two effects that lead to a significant reduction of the switching field distribution in exchange spring media. The first effect relies on a subtle mechanism of the interplay between exchange coupling between soft and hard layers and anisotropy that allows significant reduction of the switching field distribution in exchange spring media. This effect reduces the switching field distribution by about 30% compared to single-phase media. A second effect is that due to the improved thermal stability of exchange spring media over single-phase media, the jitter due to thermal fluctuation is significantly smaller for exchange spring media than for single-phase media. The influence of this overall improved switching field distribution on the transition jitter in granular recording and the bit error rate in bit-patterned magnetic recording is discussed. The transition jitter in granular recording for a distribution of Khard values of 3% in the hard layer, taking into account thermal fluctuations during recording, is estimated to be a = 0.78 nm, which is similar to the best reported calculated jitter in optimized heat-assisted recording media.

  10. Superior bit error rate and jitter due to improved switching field distribution in exchange spring magnetic recording media

    PubMed Central

    Suess, D.; Fuger, M.; Abert, C.; Bruckner, F.; Vogler, C.

    2016-01-01

    We report two effects that lead to a significant reduction of the switching field distribution in exchange spring media. The first effect relies on a subtle mechanism of the interplay between exchange coupling between soft and hard layers and anisotropy that allows significant reduction of the switching field distribution in exchange spring media. This effect reduces the switching field distribution by about 30% compared to single-phase media. A second effect is that due to the improved thermal stability of exchange spring media over single-phase media, the jitter due to thermal fluctuation is significantly smaller for exchange spring media than for single-phase media. The influence of this overall improved switching field distribution on the transition jitter in granular recording and the bit error rate in bit-patterned magnetic recording is discussed. The transition jitter in granular recording for a distribution of Khard values of 3% in the hard layer, taking into account thermal fluctuations during recording, is estimated to be a = 0.78 nm, which is similar to the best reported calculated jitter in optimized heat-assisted recording media. PMID:27245287

  11. Constrained fixed-fulcrum reverse shoulder arthroplasty improves functional outcome in epileptic patients with recurrent shoulder instability.

    PubMed

    Thangarajah, Tanujan; Higgs, Deborah; Bayley, J I L; Lambert, Simon M

    2016-07-18

    To report the results of fixed-fulcrum fully constrained reverse shoulder arthroplasty for the treatment of recurrent shoulder instability in patients with epilepsy. A retrospective review was conducted at a single facility. Cases were identified using a computerized database and all clinic notes and operative reports were reviewed. All patients with epilepsy and recurrent shoulder instability were included for study. Between July 2003 and August 2011 five shoulders in five consecutive patients with epilepsy underwent fixed-fulcrum fully constrained reverse shoulder arthroplasty for recurrent anterior shoulder instability. The mean duration of epilepsy in the cohort was 21 years (range, 5-51) and all patients suffered from grand mal seizures. Mean age at the time of surgery was 47 years (range, 32-64). The cohort consisted of four males and one female. Mean follow-up was 4.7 years (range, 4.3-5 years). There were no further episodes of instability, and no further stabilisation or revision procedures were performed. The mean Oxford shoulder instability score improved from 8 preoperatively (range, 5-15) to 30 postoperatively (range, 16-37) (P = 0.015) and the mean subjective shoulder value improved from 20 (range, 0-50) preoperatively to 60 (range, 50-70) postoperatively (P = 0.016). Mean active forward elevation improved from 71° preoperatively (range, 45°-130°) to 100° postoperatively (range, 80°-90°) and mean active external rotation improved from 15° preoperatively (range, 0°-30°) to 40° (20°-70°) postoperatively. No cases of scapular notching or loosening were noted. Fixed-fulcrum fully constrained reverse shoulder arthroplasty should be considered for the treatment of recurrent shoulder instability in patients with epilepsy.

  12. Constrained fixed-fulcrum reverse shoulder arthroplasty improves functional outcome in epileptic patients with recurrent shoulder instability

    PubMed Central

    Thangarajah, Tanujan; Higgs, Deborah; Bayley, J I L; Lambert, Simon M

    2016-01-01

    AIM: To report the results of fixed-fulcrum fully constrained reverse shoulder arthroplasty for the treatment of recurrent shoulder instability in patients with epilepsy. METHODS: A retrospective review was conducted at a single facility. Cases were identified using a computerized database and all clinic notes and operative reports were reviewed. All patients with epilepsy and recurrent shoulder instability were included for study. Between July 2003 and August 2011 five shoulders in five consecutive patients with epilepsy underwent fixed-fulcrum fully constrained reverse shoulder arthroplasty for recurrent anterior shoulder instability. The mean duration of epilepsy in the cohort was 21 years (range, 5-51) and all patients suffered from grand mal seizures. RESULTS: Mean age at the time of surgery was 47 years (range, 32-64). The cohort consisted of four males and one female. Mean follow-up was 4.7 years (range, 4.3-5 years). There were no further episodes of instability, and no further stabilisation or revision procedures were performed. The mean Oxford shoulder instability score improved from 8 preoperatively (range, 5-15) to 30 postoperatively (range, 16-37) (P = 0.015) and the mean subjective shoulder value improved from 20 (range, 0-50) preoperatively to 60 (range, 50-70) postoperatively (P = 0.016). Mean active forward elevation improved from 71° preoperatively (range, 45°-130°) to 100° postoperatively (range, 80°-90°) and mean active external rotation improved from 15° preoperatively (range, 0°-30°) to 40° (20°-70°) postoperatively. No cases of scapular notching or loosening were noted. CONCLUSION: Fixed-fulcrum fully constrained reverse shoulder arthroplasty should be considered for the treatment of recurrent shoulder instability in patients with epilepsy. PMID:27458554

  13. Improving Inertial Pedestrian Dead-Reckoning by Detecting Unmodified Switched-on Lamps in Buildings

    PubMed Central

    Jiménez, Antonio R.; Zampella, Francisco; Seco, Fernando

    2014-01-01

    This paper explores how inertial Pedestrian Dead-Reckoning (PDR) location systems can be improved with the use of a light sensor to measure the illumination gradients created when a person walks under ceiling-mounted unmodified indoor lights. The process of updating the inertial PDR estimates with the information provided by light detections is a new concept that we have named Light-matching (LM). The displacement and orientation change of a person obtained by inertial PDR is used by the LM method to accurately propagate the location hypothesis, and vice versa; the LM approach benefits the PDR approach by obtaining an absolute localization and reducing the PDR-alone drift. Even from an initially unknown location and orientation, whenever the person passes below a switched-on light spot, the location likelihood is iteratively updated until it potentially converges to a unimodal probability density function. The time to converge to a unimodal position hypothesis depends on the number of lights detected and the asymmetries/irregularities of the spatial distribution of lights. The proposed LM method does not require any intensity illumination calibration, just the pre-storage of the position and size of all lights in a building, irrespective of their current on/off state. This paper presents a detailed description of the light-matching concept, the implementation details of the LM-assisted PDR fusion scheme using a particle filter, and several simulated and experimental tests, using a light sensor-equipped Galaxy S3 smartphone and an external foot-mounted inertial sensor. The evaluation includes the LM-assisted PDR approach as well as the fusion with other signals of opportunity (WiFi, RFID, Magnetometers or Map-matching) in order to compare their contribution in obtaining high accuracy indoor localization. The integrated solution achieves a localization error lower than 1 m in most of the cases. PMID:24394599

  14. Temperature-stable lithium niobate electro-optic Q-switch for improved cold performance

    NASA Astrophysics Data System (ADS)

    Jundt, Dieter H.

    2014-10-01

    Lithium niobate (LN) is commonly used as an electro optic (EO) Q-switch material in infrared targeting lasers because of its relatively low voltage requirements and low cost compared to other crystals. A common challenge is maintaining good performance at the sub-freezing temperatures often experienced during flight. Dropping to low temperature causes a pyro-electric charge buildup on the optical faces that leads to birefringence non-uniformity and depolarization resulting in poor hold-off and premature lasing. The most common solution has been to use radioactive americium to ionize the air around the crystal and bleed off the charge, but the radioactive material requires handling and disposal procedures that can be problematic. We have developed a superior solution that is now being implemented by multiple defense system suppliers. By applying a low level thermo-chemical reduction to the LN crystal optical faces we induce a small conductivity that allows pyro-charges to dissipate. As the material gets more heavily treated, the capacity to dissipate charges improves, but the corresponding optical absorption also increases, causing insertion loss. Even though typical high gain targeting laser systems can tolerate a few percent of added loss, the thermo-chemical processing needs to be carefully optimized. We describe the results of our process optimization to minimize the insertion loss while still giving effective charge dissipation. Treatment is performed at temperatures below 500°C and a conductivity layer less than 0.5mm in depth is created that is uniform across the optical aperture. Because the conductivity is thermally activated, the charge dissipation is less effective at low temperature, and characterization needs to be performed at cold temperatures. The trade-off between optical insertion loss and potential depolarization due to low temperature operation is discussed and experimental results on the temperature dependence of the dissipation time and the

  15. Switching to a 10-day Mediterranean-style diet improves mood and cardiovascular function in a controlled crossover study.

    PubMed

    Lee, Jaime; Pase, Matthew; Pipingas, Andrew; Raubenheimer, Jessica; Thurgood, Madeline; Villalon, Lorena; Macpherson, Helen; Gibbs, Amy; Scholey, Andrew

    2015-05-01

    Even short-term adherence to a Mediterranean-style diet may benefit aspects of psychological functioning. The aim of the present study was to assess the effects of switching to a 10-d Mediterranean-style diet on mood, cognition, and cardiovascular measures. Using a crossover design, 24 women were randomly assigned to either the diet change (where they switched to a Mediterranean-style diet) or no diet change (normal diet) condition for 10 days before switching to the other condition for the same duration. Mood, cognition, and cardiovascular measures of blood pressure, blood flow velocity, and arterial stiffness were assessed at baseline and at the completion of the two diets (days 11 and 22). Independent of whether the Mediterranean-style diet was undertaken before or after the crossover, it was associated with significantly elevated contentment and alertness, and significantly reduced confusion. Additionally, aspects of cognition, such as memory recall, improved significantly as a result of switching to the Mediterranean-style diet. Regarding cardiovascular measures, there was a significant reduction in augmentation pressure associated with the Mediterranean-style diet intervention, but blood flow velocity through the common carotid artery did not change. This Mediterranean-style diet has the potential to enhance aspects of mood, cognition, and cardiovascular function in a young, healthy adult sample. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Behavioural effects of fixed speed cameras on motorways: overall improved speed compliance or kangaroo jumps?

    PubMed

    De Pauw, Ellen; Daniels, Stijn; Brijs, Tom; Hermans, Elke; Wets, Geert

    2014-12-01

    The present study evaluates the speed effects of fixed speed cameras on motorways. Two locations with speed cameras were extensively examined in a quasi-experiment: (1) a two-lane motorway and (2) a three-lane motorway, each with a posted speed limit of 120 km/h and sited in Flanders, Belgium. The effect is analysed through a before-and-after comparison of travel speeds. General time trends and fluctuations were controlled through the analysis of the speeds at comparison locations. At each of the two roads, data were gathered at five measurement points from 3 km upstream to 3.8 km downstream of the camera. Three outcomes were analysed: (1) average speed, (2) the odds of drivers exceeding the speed limit and (3) the odds of drivers exceeding the speed limit by more than 10%. Speeds decreased on average by 6.4 km/h at the camera locations. Both the odds of drivers exceeding the speed limit (-80%) and the odds of drivers exceeding the speed limit by more than 10% (-86%) decreased considerably. However, before and beyond the cameras the speeds hardly, if at all, reduced. Moreover, the analyses of the speed profiles before and beyond the cameras show that drivers do slow down quite abruptly before the camera and speed up again after passing the camera. It is concluded that a V-profile is found in the spatial speed distribution for both locations.

  17. Improved Protein Extractionand Protein Identification from Archival Formalin-fixed Paraffin-embedded Human Aortas

    PubMed Central

    Fu, Zongming; Yan, Kun; Rosenberg, Avraham; Jin, Zhicheng; Crain, Barbara; Athas, Grace; Vander Heide, Richard S; Howard, Timothy; Everett, Allen D.; Herrington, David; Van Eyk, Jennifer E.

    2014-01-01

    Purpose Evaluate combination of heat and elevated pressure to enhance protein extraction and quality of formaldehyde-fixed (FF), and FF paraffin-embedded (FFPE) aorta for proteomics. Experiment design Proteins were extracted from fresh frozen aorta at RT. FF and FFPE aortas (3 months and 15 years) were extracted at RT, heat alone, or a combination of heat and high pressure. Protein yields were compared, and digested peptides from the extracts were analyzed with mass spectrometry. Results Combined heat and elevated pressure increased protein yield from human FF or FFPE aorta compared to matched tissues with heat alone (1.5 fold) or at RT (8.3 fold), resulting in more proteins identified and with more sequence coverage. The length of storage did adversely affect the quality of proteins from FF tissue. For long term storage, aorta was preserved better with FFPE than FF alone. Periostin and MGF-E8 were demonstrated suitable for MRM assays from FFPE aorta. Conclusions and clinical relevance Combination of heat and high pressure is an effective method to extract proteins from FFPE aorta for downstream proteomics. This method opens the possibility for use of archival and often rare FFPE aortas and possibly other tissues available to proteomics for biomarker discovery and quantification. PMID:23339088

  18. Improved protein extraction and protein identification from archival formalin-fixed paraffin-embedded human aortas.

    PubMed

    Fu, Zongming; Yan, Kun; Rosenberg, Avraham; Jin, Zhicheng; Crain, Barbara; Athas, Grace; Heide, Richard S Vander; Howard, Timothy; Everett, Allen D; Herrington, David; Van Eyk, Jennifer E

    2013-04-01

    Evaluate combination of heat and elevated pressure to enhance protein extraction and quality of formalin-fixed (FF), and FF paraffin-embedded (FFPE) aorta for proteomics. Proteins were extracted from fresh frozen aorta at room temperature (RT). FF and FFPE aortas (3 months and 15 years) were extracted at RT, heat alone, or a combination of heat and high pressure. Protein yields were compared, and digested peptides from the extracts were analyzed with MS. Combined heat and elevated pressure increased protein yield from human FF or FFPE aorta compared to matched tissues with heat alone (1.5-fold) or at RT (8.3-fold), resulting in more proteins identified and with more sequence coverage. The length of storage did adversely affect the quality of proteins from FF tissue. For long-term storage, aorta was preserved better with FFPE than FF alone. Periostin and MGF-E8 were demonstrated suitable for MRM assays from FFPE aorta. Combination of heat and high pressure is an effective method to extract proteins from FFPE aorta for downstream proteomics. This method opens the possibility for use of archival and often rare FFPE aortas and possibly other tissues available to proteomics for biomarker discovery and quantification. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Performance improvements of MOEMS-based diffractive arrays: address isolation and optical switching

    NASA Astrophysics Data System (ADS)

    Panaman, Ganesh; Madison, Seth; Sano, Michael; Castracane, James

    2005-01-01

    Micro-Opto-Electro-Mechanical Systems (MOEMS) have found a variety of applications in fields such as telecommunications, spectroscopy and display technology. MOEMS-based optical switching is currently under investigation for the increased flexibility that such devices provide for reconfiguration of the I/O network for inter-chip communication applications. This potential not only adds an additional degree of freedom for adjustment of transmitter/receiver links but also allows for fine alignment of individual channels in the network link. Further, this use of diffractive arrays for specific applications combines beam steering/adjustment capabilities with the inherent wavelength dependence of the diffractive approach for channel separation and de-multiplexing. Research and development has been concentrated on the progression from single MOEMS components to parallel arrays integrated with optical source arrays for a successful feasibility demonstration. Successful development of such an approach will have a major impact of the next generation communication protocols. This paper will focus on the current status of the MOEMS research program for Free Space Optical inter-chip communication at the College of NanoScale Science and Engineering, University at Albany-SUNY (CNSE). New versions of diffractive arrays stemming from the basic MEMS Compound Grating (MCG; patent #5,999,319) have been produced through various fabrication methods including the MUMPs process1. Most MEMS components relying on electrostatic actuation tend to require high actuation voltages (>20V) compared to the typical 5V levels prevalent in conventional integrated circuits. The specific goal is to yield improved performance while minimizing the power consumption of the components. Structural modifications through the variation in the ruling/electrode spacing distance and array wiring layout through individually addressable gratings have been studied to understand effects on the actuation voltage and

  20. Improvement of Plasma Biomarkers after Switching Stroke Patients from Other Angiotensin II Type I Receptor Blockers to Olmesartan.

    PubMed

    Tada, Yoshiteru; Yagi, Kenji; Uno, Masaaki; Matsushita, Nobuhisa; Kanematsu, Yasuhisa; Kuwayama, Kazuyuki; Shimada, Kenji; Nishi, Kyoko; Hirasawa, Motohiro; Satomi, Junichiro; Kitazato, Keiko T; Kageji, Teruyoshi; Matsuura, Eiji; Nagahiro, Shinji

    2015-07-01

    Managing hypertension is crucial for preventing stroke recurrence. Some stroke patients experience resistant hypertension. In our experimental stroke model, olmesartan increased the expression of angiotensin (Ang) II converting enzyme-2. We hypothesized that switching to olmesartan affects biomarkers and the blood pressure (BP) in stroke patients whose BP is insufficiently controlled by standard doses of Ang II type I receptor blockers (ARBs) other than olmesartan. We recruited 25 patients to study our hypothesis. All had a history of stroke or silent cerebral infarction. We switched them to olmesartan (10-40 mg per day) for 12 weeks and determined their plasma level of Ang-(1-7), peroxiredoxin, oxidized low-density lipoprotein (oxLDL)/β-2-glycoprotein I (β2GPI) complex, adiponectin, high mobility group box 1 (HMGB1), and tumor necrosis factor-α (TNFα) and recorded their BP before and after olmesartan treatment. After switching the patients to olmesartan, their plasma level of Ang-(1-7) as a vasoprotective indicator and adiponectin regulating metabolic syndrome was increased, and peroxiredoxin and the oxLDL/β2GPI complex indicating its antioxidative stress and its proatherogenicity were lower than their baseline. This suggests that olmesartan may be more effective than other ARBs to improve these conditions. Neither HMGB1 nor TNFα reflecting an inflammatory response was affected, suggesting that the anti-inflammatory effects of olmesartan are similar to those of other ARBs. The recommended BP (<140/90) was obtained in 10 of the 25 patients after switching to olmesartan. No adverse events occurred. Switching from other ARBs to olmesartan may be a promising therapeutic option in patients with resistant hypertension. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  1. Fixed-Dose Triple Combination of Antihypertensive Drugs Improves Blood Pressure Control: From Clinical Trials to Clinical Practice.

    PubMed

    Mazza, Alberto; Lenti, Salvatore; Schiavon, Laura; Sacco, Antonella Paola; Dell'Avvocata, Fabio; Rigatelli, Gianluca; Ramazzina, Emilio

    2017-04-01

    Blood pressure (BP) control is the main clinical goal in the management of hypertensive patients; however, BP in most of these patients remains uncontrolled, despite the widespread availability of antihypertensive drugs as free-combination therapy. This study compared the efficacy of a fixed-dose triple combination (FDTC) of antihypertensive drugs with that of a free combination of three antihypertensives in patients with uncontrolled hypertension. Ninety-two patients (mean age 60.8 ± 12.1, 58.0% male) with uncontrolled essential hypertension (office systolic BP ≥ 140 or diastolic BP ≥ 90 mmHg) previously treated with a renin-angiotensin-aldosterone system (RAAS) inhibitor plus hydrochlorothiazide were switched to once-daily FDTC therapy with perindopril/indapamide/amlodipine (5-10/1.25-2.5/5-10 mg). Patients were age- and sex-matched with a control group of hypertensive patients receiving free-combination therapy with three drugs including a RAAS inhibitor, a diuretic, and a calcium channel blocker. Office BP and 24-h ambulatory BP monitoring (ABPM) were evaluated at baseline and after 1 and 4 months. Significant reductions in ambulatory 24-h, daytime, and nighttime systolic BP, and pulse pressure (PP) were found in the FDTC group relative to reductions seen with free-combination therapy, after the first month only of follow-up. Target BP values (mean 24-h ambulatory systolic/diastolic BP < 130/80 mmHg) were reached by more recipients of FDTC than free-combination therapy (64.8% vs. 46.9%, p < 0.05) at month 4 of follow-up, despite reductions in 24-h ABPM values from baseline being similar in both groups at this time point. FDTC of perindopril/indapamide/amlodipine was effective at reducing SBP and PP in previously treated patients with uncontrolled hypertension, and well tolerated, providing support for clinicians in choosing a fixed-dose triple combination over the free-combination of a RAAS inhibitor, a diuretic, and a calcium antagonist.

  2. Optimizing Heat Treatment of Gas Turbine Blades with a Co C Fixed Point for Improved In-service Thermocouples

    NASA Astrophysics Data System (ADS)

    Pearce, J. V.; Machin, G.; Ford, T.; Wardle, S.

    2008-02-01

    Improvement of energy efficiency of jet aircraft is achieved by operating gas turbine engines at higher temperatures. To facilitate this, gas turbine engine manufacturers are continuously developing new alloys for hot-zone turbine blades that will withstand the increased in-service temperatures. A critical part of the manufacture of these blades is heat treatment to ensure that they attain the necessary metallurgical characteristics. Current heat-treatment temperature-control requirements are at the limit of what is achievable with conventional thermocouple calibrations. A project that will allow thermocouple manufacturer CCPI Europe Ltd. to realize uncertainties of ± 1°C, or better, in the calibration of its noble metal thermocouples is described. This will be realized through implementing a Co C eutectic fixed point in CCPI’s calibration chain. As this melts at 1,324°C, very close to the heat-treatment temperatures required, low uncertainties will be obtained. This should yield an increase in effectiveness of the heat-treatment process performed by Bodycote Heat Treatments Ltd., allowing them to respond effectively to the increasingly stringent demands of engine manufacturers. Outside the current project, there is a strong requirement by industry for lower uncertainties at and above 1,300°C. Successful implementation of the current fixed point in an industrial setting is likely to result in rapid take-up by other companies, probably through the supply of ultra-low uncertainty thermocouples, looking to improve their high-temperature processes.

  3. A Switching-Mode Power Supply Design Tool to Improve Learning in a Power Electronics Course

    ERIC Educational Resources Information Center

    Miaja, P. F.; Lamar, D. G.; de Azpeitia, M.; Rodriguez, A.; Rodriguez, M.; Hernando, M. M.

    2011-01-01

    The static design of ac/dc and dc/dc switching-mode power supplies (SMPS) relies on a simple but repetitive process. Although specific spreadsheets, available in various computer-aided design (CAD) programs, are widely used, they are difficult to use in educational applications. In this paper, a graphic tool programmed in MATLAB is presented,…

  4. Continuous surface switching: An improved time-dependent self-consistent-field method for nonadiabatic dynamics

    NASA Astrophysics Data System (ADS)

    Volobuev, Yuri L.; Hack, Michael D.; Topaler, Maria S.; Truhlar, Donald G.

    2000-06-01

    We present a new semiclassical method for electronically nonadiabatic collisions. The method is a variant of the time-dependent self-consistent-field method and is called continuous surface switching. The algorithm involves a self-consistent potential trajectory surface switching approach that is designed to combine the advantages of the trajectory surface hopping approach and the Ehrenfest classical path self-consistent potential approach without their relative disadvantages. Viewed from the self-consistent perspective, it corresponds to "on-the-fly histogramming" of the Ehrenfest method by a natural decay of mixing; viewed from the surface hopping perspective, it corresponds to replacing discontinuous surface hops by continuous surface switching. In this article we present the method and illustrate it for three multidimensional cases. Accurate quantum mechanical scattering calculations are carried out for these three cases by a linear algebraic variational method, and the accurate values of reactive probabilities, quenching probabilities, and moments of final vibrational and rotational distributions are compared to the results of continuous surface switching, the trajectory surface hopping method in two representations, the time-dependent self-consistent-field method, and the Miller-Meyer classical electron method to place the results of the semiclassical methods in perspective.

  5. A Switching-Mode Power Supply Design Tool to Improve Learning in a Power Electronics Course

    ERIC Educational Resources Information Center

    Miaja, P. F.; Lamar, D. G.; de Azpeitia, M.; Rodriguez, A.; Rodriguez, M.; Hernando, M. M.

    2011-01-01

    The static design of ac/dc and dc/dc switching-mode power supplies (SMPS) relies on a simple but repetitive process. Although specific spreadsheets, available in various computer-aided design (CAD) programs, are widely used, they are difficult to use in educational applications. In this paper, a graphic tool programmed in MATLAB is presented,…

  6. An Improved Algorithm for Linear Inequalities in Pattern Recognition and Switching Theory.

    ERIC Educational Resources Information Center

    Geary, Leo C.

    This thesis presents a new iterative algorithm for solving an n by l solution vector w, if one exists, to a set of linear inequalities, A w greater than zero which arises in pattern recognition and switching theory. The algorithm is an extension of the Ho-Kashyap algorithm, utilizing the gradient descent procedure to minimize a criterion function…

  7. Immediately loaded platform-switched implants in the anterior mandible with fixed prostheses: a randomized, split-mouth, masked prospective trial.

    PubMed

    Romanos, Georgios E; Malmstrom, Hans; Feng, Changyong; Ercoli, Carlo; Caton, Jack

    2014-12-01

    Platform-switched implants have been demonstrated to maintain marginal bone-level stability after immediate loading. The present study evaluated crestal bone loss and soft tissue stability around ANKYLOS plus® implants (A-implants) and Certain® PREVAIL(TM) (B-implants). Patients were identified to receive three A- or three B-implants on each side of their mandibles, with randomization. All implants were loaded immediately after their insertion and splinted with a cemented provisional prosthesis. Final prostheses were delivered 3 months after implantation. Peri-implant crestal bone loss, gingival recession, and other soft tissue changes were evaluated throughout a 2-year follow-up. A total of one hundred seven implants were placed in 18 patients. Two of the group A-implants and one group B-implant failed. At the final 24-month assessment, bone loss of at least 2 mm (mesially or distally) was recorded at 5 of the 44 surviving A-implants (11%) and 33 of the 47 B-implants (70%), a success rate of 88.63% for the A- and 29.78% for the B-implants. Significant changes in the level of the crestal bone loss around immediately loaded platform-switched dental implants seem to be related to the platform shape and size, as well as the implant-abutment connection, when abutments are not removed. © 2013 Wiley Periodicals, Inc.

  8. Improved reproducibility in genome-wide DNA methylation analysis for PAXgene-fixed samples compared with restored formalin-fixed and paraffin-embedded DNA.

    PubMed

    Andersen, Gitte Brinch; Hager, Henrik; Hansen, Lise Lotte; Tost, Jörg

    2015-01-01

    Formalin fixation has been the standard method for conservation of clinical specimens for decades. However, a major drawback is the high degradation of nucleic acids, which complicates its use in genome-wide analyses. Unbiased identification of biomarkers, however, requires genome-wide studies, precluding the use of the valuable archives of specimens with long-term follow-up data. Therefore, restoration protocols for DNA from formalin-fixed and paraffin-embedded (FFPE) samples have been developed, although they are cost-intensive and time-consuming. An alternative to FFPE and snap-freezing is the PAXgene Tissue System, developed for simultaneous preservation of morphology, proteins, and nucleic acids. In the current study, we compared the performance of DNA from either PAXgene or formalin-fixed tissues to snap-frozen material for genome-wide DNA methylation analysis using the Illumina 450K BeadChip. Quantitative DNA methylation analysis demonstrated that the methylation profile in PAXgene-fixed tissues showed, in comparison with restored FFPE samples, a higher concordance with the profile detected in frozen samples. We demonstrate, for the first time, that DNA from PAXgene conserved tissue performs better compared with restored FFPE DNA in genome-wide DNA methylation analysis. In addition, DNA from PAXgene tissue can be directly used on the array without prior restoration, rendering the analytical process significantly more time- and cost-effective. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Improved Resistance Switching Stability in Fe-Doped ZnO Thin Films Through Pulsed Magnetic Field Annealing

    NASA Astrophysics Data System (ADS)

    Xu, Hongtao; Wu, Changjin; Xiahou, Zhao; Jung, Ranju; Li, Ying; Liu, Chunli

    2017-03-01

    Five percent of Fe-doped ZnO (ZnO:Fe) thin films were deposited on Pt/TiO2/SiO2/Si substrates by a spin-coating method. The films were annealed without (ZnO:Fe-0T) and with a pulsed magnetic field of 4 T (ZnO:Fe-4TP) to investigate the magnetic annealing effect on the resistance switching (RS) behavior of the Pt/ZnO:Fe/Pt structures. Compared with the ZnO:Fe-0T film, the ZnO:Fe-4TP film showed improved RS performance regarding the stability of the set voltage and the resistance of the high resistance state. Transmission electron microscopy and X-ray photoelectron spectroscopy analyses revealed that the ZnO:Fe-4TP film contains more uniform grains and a higher density of oxygen vacancies, which promote the easier formation of conducting filaments along similar paths and the stability of switching parameters. These results suggest that external magnetic fields can be used to prepare magnetic oxide thin films with improved resistance switching performance for memory device applications.

  10. Improved Resistance Switching Stability in Fe-Doped ZnO Thin Films Through Pulsed Magnetic Field Annealing.

    PubMed

    Xu, Hongtao; Wu, Changjin; Xiahou, Zhao; Jung, Ranju; Li, Ying; Liu, Chunli

    2017-12-01

    Five percent of Fe-doped ZnO (ZnO:Fe) thin films were deposited on Pt/TiO2/SiO2/Si substrates by a spin-coating method. The films were annealed without (ZnO:Fe-0T) and with a pulsed magnetic field of 4 T (ZnO:Fe-4TP) to investigate the magnetic annealing effect on the resistance switching (RS) behavior of the Pt/ZnO:Fe/Pt structures. Compared with the ZnO:Fe-0T film, the ZnO:Fe-4TP film showed improved RS performance regarding the stability of the set voltage and the resistance of the high resistance state. Transmission electron microscopy and X-ray photoelectron spectroscopy analyses revealed that the ZnO:Fe-4TP film contains more uniform grains and a higher density of oxygen vacancies, which promote the easier formation of conducting filaments along similar paths and the stability of switching parameters. These results suggest that external magnetic fields can be used to prepare magnetic oxide thin films with improved resistance switching performance for memory device applications.

  11. Efficacy and safety of switching to latanoprost 0.005%–timolol maleate 0.5% fixed-combination eyedrops from an unfixed combination for 36 months

    PubMed Central

    Inoue, Kenji; Okayama, Ryoko; Higa, Risako; Tomita, Goji

    2014-01-01

    Purpose We prospectively investigated the intraocular pressure (IOP)-reducing effect, the visual field-maintenance effect, and the adverse reactions caused by administration of latanoprost/timolol maleate fixed-combination eyedrops for 3 years. Subjects and methods The subjects were 162 patients (162 eyes) with glaucoma or ocular hypotension who were using latanoprost and timolol maleate eyedrops concomitantly. The latanoprost and timolol maleate eyedrop regimen was discontinued without any washout period and subsequently changed to a latanoprost–timolol maleate fixed-combination eyedrop regimen. IOP values before the change and at 6, 12, 18, 24, 30, and 36 months after the change were measured and compared. The Humphrey visual field test was conducted before the change and at 12, 24, and 36 months after the change, and mean-deviation values were compared. Adverse reactions were assessed at every checkup. Results The IOPs before the change and at 6–36 months after the change were 15.2±3.3 mmHg and 14.3–15.2 mmHg, respectively, and a significant decrease was observed at 36 months after the change (P<0.01). Mean-deviation values before the change and at 12–36 months after the change were −9.11±6.94 dB and −10.08 to −9.22 dB, respectively, and these values were not significantly different (P=0.2148). Within the 36-month period, the eyedrops were discontinued because of insufficient IOP decrease in 33 cases (20.4%) and adverse reactions in eleven cases (6.8%). Conclusion IOP and the visual field were maintained for 3 years when a latanoprost and timolol maleate eyedrop regimen was changed to a latanoprost–timolol maleate fixed-combination eyedrop regimen. However, administration of the latanoprost–timolol maleate fixed-combination eyedrops was discontinued in approximately 27% of cases because of insufficient IOP decrease and adverse reactions. PMID:25061275

  12. A Fixed-Wing Aircraft Simulation Tool for Improving the efficiency of DoD Acquisition

    DTIC Science & Technology

    2015-10-05

    forces and displacements are interpolated between the two models (KCFD and Sierra/SD) using the same spline interpolation schemes as are used with...order. Future improvements to the Sierra/SD component will allow coupling that results in a scheme with globally 2nd- order temporal accuracy. The Sierra...3.8M prisms, and 19.5K pyramids . The aerodynamic volume mesh used for the GBU-38 in the simulation has 1.6M tetrahedra, 2.4M prisms, and 14.4K

  13. Verbal to visual code switching improves working memory in older adults: an fMRI study.

    PubMed

    Osaka, Mariko; Otsuka, Yuki; Osaka, Naoyuki

    2012-01-01

    The effect of verbal to visual code switching training on working memory performance was investigated in individuals aged 63 and older. During verbal working memory task performance, the training group (n = 25) was introduced to a verbal to visual code switching strategy while the control group (n = 25) was not exposed to such a strategy. Working memory recognition accuracy was enhanced only in the training group. To explore the neural substrates underlying these strategy effects, fMRI was used to measure brain activity in both groups during working memory task performance before and after an attention training period. In a comparison between pre- and post-training sessions, results showed increased activation in the anterior cingulate cortex (ACC). Relative to the control group, the post-training group exhibited increased activation in the left and right inferior parietal lobules (IPLs) and right superior parietal lobule (SPL). These findings suggest that use of a verbal to visual code switching strategy may assist older individuals in the maintenance of information in working memory.

  14. Improving correct switching rates in a 'hands-free' environmental control system.

    PubMed

    Craig, Ashley; Tran, Yvonne; Craig, Daniel; Thuraisingham, Ranjit

    2005-12-01

    One potential negative impact on the quality of life of a spinal cord injured person is the loss of the ability to control devices in their immediate environment. Consequently, research and development has been conducted on technology designed to restore some measure of independence by providing means of control over these devices. A previous assistive device using changes in brain signals from eye closure as its switching system was created. Brain signals were processed using spectral analysis and although this was a successful technique, there were limitations that resulted in higher than desired switching errors. This paper presents results of an alternative method for processing brain signals as the basis for switching, called fractal dimension. In comparison to the spectral technique, the fractal dimension technique was successful in reducing the number of false positive and false negative errors. Additionally, it eliminated the need for a baseline setup for this system. This suggests that fractal dimension is a potentially viable method for analysing brain signals for use in assistive control systems.

  15. Verbal to visual code switching improves working memory in older adults: an fMRI study

    PubMed Central

    Osaka, Mariko; Otsuka, Yuki; Osaka, Naoyuki

    2012-01-01

    The effect of verbal to visual code switching training on working memory performance was investigated in individuals aged 63 and older. During verbal working memory task performance, the training group (n = 25) was introduced to a verbal to visual code switching strategy while the control group (n = 25) was not exposed to such a strategy. Working memory recognition accuracy was enhanced only in the training group. To explore the neural substrates underlying these strategy effects, fMRI was used to measure brain activity in both groups during working memory task performance before and after an attention training period. In a comparison between pre- and post-training sessions, results showed increased activation in the anterior cingulate cortex (ACC). Relative to the control group, the post-training group exhibited increased activation in the left and right inferior parietal lobules (IPLs) and right superior parietal lobule (SPL). These findings suggest that use of a verbal to visual code switching strategy may assist older individuals in the maintenance of information in working memory. PMID:22363281

  16. Design improvement of permanent magnet flux switching motor with dual rotor structure

    NASA Astrophysics Data System (ADS)

    Soomro, H. A.; Sulaiman, E.; Kumar, R.; Rahim, N. S.

    2017-08-01

    This paper presents design enhancement to reduce permanent magnet (PM) volume for 7S-6P-7S dual rotor permanent magnet flux-switching machines (DRPMFSM) for electric vehicle application. In recent years, Permanent magnet flux switching (PMFS) motor and a new member of brushless permanent magnet machine are prominently used for the electric vehicle. Though, more volume of Rare-Earth Permanent Magnet (REPM) is used to increase the cost and weight of these motors. Thus, to overcome the issue, new configuration of 7S-6P- 7S dual rotor permanent magnet flux-switching machine (DRPMFSM) has been proposed and investigated in this paper. Initially proposed 7S-6P-7S DRPMFSM has been optimized using “deterministic optimization” to reduce the volume of PM and to attain optimum performances. In addition, the performances of initial and optimized DRPMFSM have been compared such that back-emf, cogging torque, average torque, torque and power vs speed performances, losses and efficiency have been analysed by 2D-finite element analysis (FEA) using the JMAG- Designer software ver. 14.1. Consequently, the final design 7S-6P-7S DRPMFSM has achieved the efficiency of 83.91% at reduced PM volume than initial design to confirm the better efficient motor for HEVs applications.

  17. Improved operation of a microwave pulse compressor with a laser-triggered high-pressure gas plasma switch

    SciTech Connect

    Shlapakovski, A.; Gorev, S.; Krasik, Ya. E.

    2016-08-15

    The influence of laser beam parameters on the output pulses of a resonant microwave compressor with a laser-triggered plasma switch was investigated. The S-band compressor, consisting of a rectangular waveguide-based cavity and H-plane waveguide tee with a shorted side arm, was filled with pressurized dry air and pumped by 1.8-μs-long microwave pulses of up to 450 kW power. A Nd:YAG laser was used to ignite the gas discharge in the tee side arm for output pulse extraction. The laser beam (at 213 nm or 532 nm) was directed along the RF electric field lines. It was found that the compressor operated most effectively when the laser beam was focused at the center of the switch waveguide cross-section. In this case, the power extraction efficiency reached ∼47% at an output power of ∼14 MW, while when the laser beam was not focused the maximal extraction efficiency was only ∼20% at ∼6 MW output power. Focusing the laser beam resulted also in a dramatic decrease (down to <1 ns) in the delay of the output pulses' appearance with respect to the time of the beam's entrance into the switch, and the jitter of the output pulses' appearance was minimized. In addition, the quality of the output pulses' waveform was significantly improved.

  18. Improved operation of a microwave pulse compressor with a laser-triggered high-pressure gas plasma switch

    NASA Astrophysics Data System (ADS)

    Shlapakovski, A.; Gorev, S.; Krasik, Ya. E.

    2016-08-01

    The influence of laser beam parameters on the output pulses of a resonant microwave compressor with a laser-triggered plasma switch was investigated. The S-band compressor, consisting of a rectangular waveguide-based cavity and H-plane waveguide tee with a shorted side arm, was filled with pressurized dry air and pumped by 1.8-μs-long microwave pulses of up to 450 kW power. A Nd:YAG laser was used to ignite the gas discharge in the tee side arm for output pulse extraction. The laser beam (at 213 nm or 532 nm) was directed along the RF electric field lines. It was found that the compressor operated most effectively when the laser beam was focused at the center of the switch waveguide cross-section. In this case, the power extraction efficiency reached ˜47% at an output power of ˜14 MW, while when the laser beam was not focused the maximal extraction efficiency was only ˜20% at ˜6 MW output power. Focusing the laser beam resulted also in a dramatic decrease (down to <1 ns) in the delay of the output pulses' appearance with respect to the time of the beam's entrance into the switch, and the jitter of the output pulses' appearance was minimized. In addition, the quality of the output pulses' waveform was significantly improved.

  19. Hollow fiber optics with improved durability for high-peak-power pulses of Q-switched Nd:YAG lasers.

    PubMed

    Matsuura, Yuji; Tsuchiuchi, Akio; Noguchi, Hiroshi; Miyagi, Mitsunobu

    2007-03-10

    To improve the damage threshold of hollow optical waveguides for transmitting Q-switched Nd:YAG laser pulses, we optimize the metallization processes for the inner coating of fibers. For silver-coated hollow fiber as the base, second, and third Nd:YAG lasers, drying silver films at a moderate temperature and with inert gas flow is found to be effective. By using this drying process, the resistance to high-peak-power optical pulse radiation is drastically improved for fibers fabricated with and without the sensitizing process. The maximum peak power transmitted in the fiber is greater than 20 MW. To improve the energy threshold of aluminum-coated hollow fibers for the fourth and fifth harmonics of Nd:YAG lasers, a thin silver film is added between the aluminum film and the glass substrate to increase adhesion of the aluminum coating. By using this primer layer, the power threshold improves to 3 MW for the fourth harmonics of a Q-switched Nd:YAG laser light.

  20. Pretreatment methods to improve nerve immunostaining in corneas from long-term fixed embryonic quail eyes

    NASA Technical Reports Server (NTRS)

    Barrett, J. E.; Wells, D. C.; Conrad, G. W.

    1999-01-01

    Pretreatment methods were used to improve neurofilament immunostaining in corneas from embryonic day 16 Japanese quail corneas that had been stored in fixative solution for several months. A sequential combination of the following three pretreatments: brief microwave heating in saline, followed by extraction with sodium dodecyl sulfate (SDS) at 37 degrees C, followed by digestion with hyaluronidase at 37 degrees C, produced significantly increased antibody staining of corneal neurofilament proteins, compared with embryonic corneas subjected to no prior pretreatments or to single or two-step protocols. After applying the sequence of all three pretreatments, darkest nerve staining and increased numbers of fine branches were observed, together with lower background staining. Thus, the result of applying the three-step pretreatment sequence is better than that of applying any of its component single pretreatments or even combinations of any two of them. These findings therefore suggest that each of these three pretreatments causes a unique effect, beneficial to immunostaining of neurofilament proteins, and that their individual effects are independent and additive. In addition to embryonic corneas, the three-step procedure also may be useful for immunostaining of nerves in other very delicate, highly-hydrated tissues containing an abundance of extracellular matrix.

  1. Switch from Sodium Phenylbutyrate to Glycerol Phenylbutyrate Improved Metabolic Stability in an Adolescent with Ornithine Transcarbamylase Deficiency.

    PubMed

    Laemmle, Alexander; Stricker, Tamar; Häberle, Johannes

    2017-01-01

    A male patient, born in 1999, was diagnosed with ornithine transcarbamylase deficiency as neonate and was managed with a strict low-protein diet supplemented with essential amino acids, L-citrulline, and L-arginine as well as sodium benzoate. He had an extensive history of hospitalizations for hyperammonemic crises throughout childhood and early adolescence, which continued after the addition of sodium phenylbutyrate in 2009. In December 2013 he was switched to glycerol phenylbutyrate, and his metabolic stability was greatly improved over the following 7 months prior to liver transplant.

  2. Modeling and performance analysis of an improved movement-based location management scheme for packet-switched mobile communication systems.

    PubMed

    Chung, Yun Won; Kwon, Jae Kyun; Park, Suwon

    2014-01-01

    One of the key technologies to support mobility of mobile station (MS) in mobile communication systems is location management which consists of location update and paging. In this paper, an improved movement-based location management scheme with two movement thresholds is proposed, considering bursty data traffic characteristics of packet-switched (PS) services. The analytical modeling for location update and paging signaling loads of the proposed scheme is developed thoroughly and the performance of the proposed scheme is compared with that of the conventional scheme. We show that the proposed scheme outperforms the conventional scheme in terms of total signaling load with an appropriate selection of movement thresholds.

  3. Improvement in encrustation removal from artworks using multi pulse Q-switched laser

    NASA Astrophysics Data System (ADS)

    Marczak, Jan; Jach, Karol; Sarzyński, Antoni

    2005-09-01

    The paper presents application of laser radiation for cleaning of monuments and art works, using Q -switched Nd:YAG laser generating high power series of pulses in so called "burst mode". The time width of pulse train is 200 ÷ 300 μs. The oscilloscope traces of pulse repetition frequency and the results of energy measurements are shown. Numerical model of interaction of high power laser pulse with graphite layer of aluminium substrate on the base of equations in one-dimensional hydrodynamic approximation is presented. The results of calculations of graphite removal process for single pulse and train of laser pulses are in qualitative agreement with the results of measurements.

  4. Fault tolerant control for switching discrete-time systems with delays: an improved cone complementarity approach

    NASA Astrophysics Data System (ADS)

    Benzaouia, Abdellah; Ouladsine, Mustapha; Ananou, Bouchra

    2014-10-01

    In this paper, fault tolerant control problem for discrete-time switching systems with delay is studied. Sufficient conditions of building an observer are obtained by using multiple Lyapunov function. These conditions are worked out in a new way, using cone complementarity technique, to obtain new LMIs with slack variables and multiple weighted residual matrices. The obtained results are applied on a numerical example showing fault detection, localisation of fault and reconfiguration of the control to maintain asymptotic stability even in the presence of a permanent sensor fault.

  5. A Passive Cavity Concept for Improving the Off-Design Performance of Fixed-Geometry Exhaust Nozzles

    NASA Technical Reports Server (NTRS)

    Asbury, Scott C.; Gunther, Christopher L.; Hunter, Craig A.

    1996-01-01

    An investigation was conducted in the model preparation area of the Langley 16-Foot Transonic Tunnel to study a passive cavity concept for improving the off-design performance of fixed-geometry exhaust nozzles. Passive cavity ventilation (through a porous surface) was applied to divergent flap surfaces and tested at static conditions in a sub-scale, nonaxisymmetric, convergent-divergent nozzle. As part of a comprehensive investigation, force, moment and pressure measurements were taken and focusing schlieren flow visualization was obtained for a baseline configuration and D passive cavity configurations. All tests were conducted with no external flow and high-pressure air was used to simulate jet-exhaust flow at nozzle pressure ratios from 1.25 to approximately 9.50. Results indicate that baseline nozzle performance was dominated by unstable shock-induced boundary-layer separation at off-design conditions, which came about through the natural tendency of overexpanded exhaust flow to satisfy conservation requirements by detaching from the nozzle divergent flaps. Passive cavity ventilation added the ability to control off-design separation in the nozzle by either alleviating separation or encouraging stable separation of the exhaust flow. Separation alleviation offers potential for installed nozzle performance benefits by reducing drag at forward flight speeds, even though it may reduce off-design static thrust efficiency as much as 3.2 percent. Encouraging stable separation of the exhaust flow offers significant performance improvements at static, low NPR and low Mach number flight conditions by improving off-design static thrust efficiency as much as 2.8 percent. By designing a fixed-geometry nozzle with fully porous divergent flaps, where both cavity location and percent open porosity of the flaps could be varied, passive flow control would make it possible to improve off-design nozzle performance across a wide operating range. In addition, the ability to

  6. Optimizing Stem Length To Improve Ligand Selectivity in a Structure-Switching Cocaine-Binding Aptamer.

    PubMed

    Neves, Miguel A D; Shoara, Aron A; Reinstein, Oren; Abbasi Borhani, Okty; Martin, Taylor R; Johnson, Philip E

    2017-10-02

    Understanding how aptamer structure and function are related is crucial in the design and development of aptamer-based biosensors. We have analyzed a series of cocaine-binding aptamers with different lengths of their stem 1 in order to understand the role that this stem plays in the ligand-induced structure-switching binding mechanism utilized in many of the sensor applications of this aptamer. In the cocaine-binding aptamer, the length of stem 1 controls whether the structure-switching binding mechanism for this aptamer occurs or not. We varied the length of stem 1 from being one to seven base pairs long and found that the structural transition from unfolded to folded in the unbound aptamer is when the aptamer elongates from 3 to 4 base pairs in stem 1. We then used this knowledge to achieve new binding selectivity of this aptamer for quinine over cocaine by using an aptamer with a stem 1 two base pairs long. This selectivity is achieved by means of the greater affinity quinine has for the aptamer compared with cocaine. Quinine provides enough free energy to both fold and bind the 2-base pair-long aptamer while cocaine does not. This tuning of binding selectivity of an aptamer by reducing its stability is likely a general mechanism that could be used to tune aptamer specificity for tighter binding ligands.

  7. Improvement of plant growth and seed yield in Jatropha curcas by a novel nitrogen-fixing root associated Enterobacter species

    PubMed Central

    2013-01-01

    Background Jatropha curcas L. is an oil seed producing non-leguminous tropical shrub that has good potential to be a fuel plant that can be cultivated on marginal land. Due to the low nutrient content of the targeted plantation area, the requirement for fertilizer is expected to be higher than other plants. This factor severely affects the commercial viability of J. curcas. Results We explored the feasibility to use endophytic nitrogen-fixing bacteria that are native to J. curcas to improve plant growth, biomass and seed productivity. We demonstrated that a novel N-fixing endophyte, Enterobacter sp. R4-368, was able to colonize in root and stem tissues and significantly promoted early plant growth and seed productivity of J. curcas in sterilized and non-sterilized soil. Inoculation of young seedling led to an approximately 57.2% increase in seedling vigour over a six week period. At 90 days after planting, inoculated plants showed an average increase of 25.3%, 77.7%, 27.5%, 45.8% in plant height, leaf number, chlorophyll content and stem volume, respectively. Notably, inoculation of the strain led to a 49.0% increase in the average seed number per plant and 20% increase in the average single seed weight when plants were maintained for 1.5 years in non-sterilized soil in pots in the open air. Enterobacter sp. R4-368 cells were able to colonize root tissues and moved systemically to stem tissues. However, no bacteria were found in leaves. Promotion of plant growth and leaf nitrogen content by the strain was partially lost in nifH, nifD, nifK knockout mutants, suggesting the presence of other growth promoting factors that are associated with this bacterium strain. Conclusion Our results showed that Enterobacter sp. R4-368 significantly promoted growth and seed yield of J. curcas. The application of the strains is likely to significantly improve the commercial viability of J. curcas due to the reduced fertilizer cost and improved oil yield. PMID:24083555

  8. Switching photo-stimulated males between groups of goats does not improve the reproductive response during the male effect.

    PubMed

    Loya-Carrera, J; Bedos, M; Ponce-Covarrubias, J L; Hernández, H; Chemineau, P; Keller, M; Delgadillo, J A

    2014-04-01

    We aimed to determine whether the daily exchange of photo-stimulated males among subgroups of females improved the reproductive response of anestrous goats exposed to males. Bucks were rendered sexually active during the rest season by exposure to 2.5 months of long days from November 1st. In April, males (n=3) were put in contact with three subgroups of anestrous goats (one male per 12 females) where they remained throughout the study, constituting the fixed-group. Other males (n=3) were put in contact with three subgroups of females (one male per 11-12 females) and were rotated daily among them, constituting the rotated-group. The sexual behavior of all males was registered from 08:00 to 09:00 on days 0, 1, 2, and 8 after exchanging the males from the subgroups of females. Ovulation and pregnancy rates were determined by transrectal ultrasonography. The occurrences of ano-genital sniffing, nudging (days 1, 2, and 8), and mounting attempts (days 2 and 8) were greater in the rotated than in the fixed-group (P<0.01). The proportions of females that ovulated did not differ among goats from the fixed (92%) and rotated-group (94%; P>0.05). The proportion of pregnant females and the fertility at kidding did not differ between those from the rotated (79% and 59%) and fixed-group (83% and 61%; P>0.05). We conclude that the daily exchange of photo-stimulated males among subgroups induced an increase of their sexual behavior, but does not improve the pregnancy rates in seasonal anestrous goats. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Improvement of deoxidization efficiency of nitric monoxide by shortening pulse width of semiconductor opening switch pulse power generator

    NASA Astrophysics Data System (ADS)

    Kakuta, Takatoshi; Yagi, Ippei; Takaki, Koichi

    2015-01-01

    The deoxidization efficiency of nitric monoxide (NO) was improved by shortening the pulse width of the voltage applied to a corona reactor. The deoxidization efficiency of NO was evaluated as the NO removal efficiency in nitrogen (N2) gas containing 200 ppm NO. The corona reactor had a coaxial geometry and consisted of center high-voltage wire and outer grounded cylinder electrodes. A nanosecond high-voltage pulse was generated using an inductive energy storage pulse power circuit with a semiconductor opening switch and was applied to the center wire electrode in the corona reactor. Fast recovery diodes were utilized as a semiconductor opening switch. The pulse width of the applied voltage was reduced from 21 to 14 ns with the arrester connected in parallel to the reactor. The energy efficiency for NO removal was improved from 8.2 to 35.7 g kW-1 h-1 with the arrester connected. The pulse width was also reduced to 8 ns by optimizing the circuit parameters. It was confirmed from observation with an intensified charge-coupled device (ICCD) camera that the streamer corona discharge transited to a glowlike discharge after the streamer propagated from the center wire electrode to the outer cylinder electrode. The duration of the glowlike phase was reduced with the arrester connected. The energy consumed in the glowlike phase was also reduced from 15.7 to 4.6 mJ with the arrester connected.

  10. State feedback control of switched linear systems: An LMI approach

    NASA Astrophysics Data System (ADS)

    Montagner, V. F.; Leite, V. J. S.; Oliveira, R. C. L. F.; Peres, P. L. D.

    2006-10-01

    This paper addresses the problem of state feedback control of continuous-time switched linear systems with arbitrary switching rules. A quadratic Lyapunov function with a common matrix is used to derive a stabilizing switching control strategy that guarantees: (i) the assignment of all the eigenvalues of each linear subsystem inside a chosen circle in the left-hand half of the complex plane; (ii) a minimum disturbance attenuation level for the closed-loop switched system. The proposed design conditions are given in terms of linear matrix inequalities that encompass previous results based on quadratic stability conditions with fixed control gains. Although the quadratic stability based on a fixed Lyapunov matrix has been widely used in robust control design, the use of this condition to provide a convex design method for switching feedback gains has not been fully investigated. Numerical examples show that the switching control strategy can cope with more stringent design specifications than the fixed gain strategy, being useful to improve the performance of this class of systems.

  11. Control of the estrous cycle to improve fertility for fixed-time artificial insemination in beef cattle: a review.

    PubMed

    Lamb, G C; Dahlen, C R; Larson, J E; Marquezini, G; Stevenson, J S

    2010-04-01

    Early estrus-synchronization protocols focused on regressing the corpus luteum (CL) with an injection of PGF(2alpha) followed by detection of estrus or involved the use of exogenous progestins that prevent estrus from occurring. Later, protocols combining the use of PGF(2alpha) and exogenous progestins were developed. Gonadotropin-releasing hormone was utilized to control follicular waves, synchronize ovulation, or to luteinize large dominant follicles. Our research aimed to develop reliable protocols that 1) relied solely on fixed-timed AI (TAI); 2) required a maximum of 3 animal handlings, and 3) were successful in estrous-cycling and noncycling females. In cows, insertion of an intravaginal progesterone insert during the 7-d interval between the initial GnRH and PGF(2alpha) injections enhanced pregnancy rates by 9 to 10%. In a multi-location study, a TAI protocol yielded pregnancy rates similar to a protocol involving detection of estrus plus a fixed-time clean-up AI for females not detected in estrus (54 vs. 58%, respectively, for cows and 53 vs. 57%, respectively, for heifers). Initiation of estrous cycles in noncycling cows is likely the primary manner in which beef producers may improve fertility in response to estrus synchronization and TAI protocols. Treatment of noncycling females with progesterone and GnRH increases the percentage of cycling females and improves fertility to a TAI, but inducing cyclicity with hCG failed to enhance fertility in TAI protocols. Supplementing progesterone after TAI failed to increase pregnancy rates in beef cattle. In contrast, administration of hCG 7 d after TAI induced an accessory CL, increased progesterone, and tended to enhance pregnancy rates. Development of TAI protocols that reduce the hassle factors associated with ovulation synchronization and AI provide cattle producers efficient and effective tools for capturing selective genetic traits of economic consequences. Location variables, however, which may include

  12. The improved resistive switching properties of TaOx-based RRAM devices by using WNx as bottom electrode

    NASA Astrophysics Data System (ADS)

    Zhou, Qigang; Zhai, Jiwei

    2013-02-01

    The WNx films were successfully prepared on silicon-based substrates as bottom electrodes for the resistive random access memory (RRAM) cells in Pt (top)/TaOx/WNx (bottom) sandwich structure. The reproducible resistive switching (RS) characteristics of these cells were studied systematically for RRAM applications. The advantages of adopting WNx instead of Pt as bottom electrode material were demonstrated, such as the improvement of the low resistive state value, the RS endurance and the uniformity of RS parameters. The X-ray photoelectron spectroscopy revealed that both the oxygen vacancies in the TaOx film and the interfacial tungsten oxynitride (WON) layer formed between the dielectric TaOx film and the WNx bottom electrode play key roles in the RS performance improvement.

  13. Single-strand DNA library preparation improves sequencing of formalin-fixed and paraffin-embedded (FFPE) cancer DNA

    PubMed Central

    Stiller, Mathias; Sucker, Antje; Griewank, Klaus; Aust, Daniela; Baretton, Gustavo Bruno; Schadendorf, Dirk; Horn, Susanne

    2016-01-01

    DNA derived from formalin-fixed and paraffin-embedded (FFPE) tissue has been a challenge to large-scale genomic sequencing, due to its low quality and quantities. Improved techniques enabling the genome-wide analysis of FFPE material would be of great value, both from a research and clinical perspective. Comparing a single-strand DNA library preparation method originally developed for ancient DNA to conventional protocols using double-stranded DNA derived from FFPE material we obtain on average 900-fold more library molecules and improved sequence complexity from as little as 5 ng input DNA. FFPE DNA is highly fragmented, usually below 100bp, and up to 60% of reads start after or end prior to adenine residues, suggesting that crosslinks predominate at adenine residues. Similar to ancient DNA, C > T substitutions are slightly increased with maximum rates up to 3% at the ends of molecules. In whole exome sequencing of single-strand libraries from lung, breast, colorectal, prostate and skin cancers we identify known cancer mutations. In summary, we show that single-strand library preparation enables genomic sequencing, even from low amounts of degraded FFPE DNA. This method provides a clear advantage both in research and clinical settings, where FFPE material (e.g. from biopsies) often is the only source of DNA available. Improving the genetic characterization that can be performed on conventional archived FFPE tissue, the single-strand library preparation allows scarce samples to be used in personalized medicine and enables larger sample sizes in future sequencing studies. PMID:27463017

  14. Phenotypic and molecular characterisation of efficient nitrogen-fixing Azotobacter strains from rice fields for crop improvement.

    PubMed

    Sahoo, Ranjan K; Ansari, Mohammad W; Dangar, Tushar K; Mohanty, Santanu; Tuteja, Narendra

    2014-05-01

    Biological nitrogen fixation (BNF) is highly effective in the field and potentially useful to reduce adverse effects chemical fertilisers. Here, Azotobacter species were selected via phenotypic, biochemical and molecular characterisations from different rice fields. Acetylene reduction assay of Azotobacter spp. showed that Azotobacter vinelandii (Az3) fixed higher amount of nitrogen (121.09 nmol C2H4 mg(-1) bacteria h(-1)). Likewise, its plant growth functions, viz. siderophore, hydrogen cyanide, salicylic acid, IAA, GA3, zeatin, NH3, phosphorus solubilisation, ACC deaminase and iron tolerance, were also higher. The profile of gDNA, plasmid DNA and cellular protein profile depicted inter-generic and inter-specific diversity among the isolates of A. vinelandii. The PCR-amplified genes nifH, nifD and nifK of 0.87, 1.4 and 1.5 kb , respectively, were ascertained by Southern blot hybridisation in isolates of A. vinelandii. The 16S rRNA sequence from A. vinelandii (Az3) was novel, and its accession number (JQ796077) was received from NCBI data base. Biofertiliser formulation of novel A. vinelandii isolates along with commercial one was evaluated in rice (Oriza sativa L. var. Khandagiri) fields. The present finding revealed that treatment T4 (Az3) (A. vinelandii) are highly efficient to improved growth and yield of rice crop.

  15. Transversally diode-pumped Q-switched Nd:YAG laser with improved power and spatial characteristics

    NASA Astrophysics Data System (ADS)

    Bezyazychnaya, T. V.; Bogdanovich, M. V.; Grigor'ev, A. V.; Kabanov, V. V.; Kostik, O. E.; Lebiadok, Y. V.; Lepchenkov, K. V.; Mashko, V. V.; Ryabtsev, A. G.; Ryabtsev, G. I.; Shchemelev, M. A.; Teplyashin, L. L.

    2013-11-01

    The power and output beam spatial properties of the transversally diode-pumped Q-switched Nd:YAG laser with the active element surrounded by the low-absorption light-scattering layer have been investigated. The layer consisted of the bonding agent in which the solid particles, like aluminum oxide or magnesium oxide, effectively scattering the light was uniformly distributed. The particle diameter was mainly in the range of 2-5 μm. It has been shown that application of such layer to the diode-pumped Q-switched Nd:YAG laser head allows suppressing the amplified spontaneous emission and/or internally circulating parasitic lasing modes. At the optimized concentration of the light-scattering solid particles the output lasing pulses with the energy of 188-210 mJ (the wavelength of 1064 nm, the pulse repetition rate of 30 Hz) and improved spatial characteristics were obtained using the pump unit based on three laser diode matrixes.

  16. Improvement and performance evaluation of the perturbation source method for an exact Monte Carlo perturbation calculation in fixed source problems

    NASA Astrophysics Data System (ADS)

    Sakamoto, Hiroki; Yamamoto, Toshihiro

    2017-09-01

    This paper presents improvement and performance evaluation of the ;perturbation source method;, which is one of the Monte Carlo perturbation techniques. The formerly proposed perturbation source method was first-order accurate, although it is known that the method can be easily extended to an exact perturbation method. A transport equation for calculating an exact flux difference caused by a perturbation is solved. A perturbation particle representing a flux difference is explicitly transported in the perturbed system, instead of in the unperturbed system. The source term of the transport equation is defined by the unperturbed flux and the cross section (or optical parameter) changes. The unperturbed flux is provided by an ;on-the-fly; technique during the course of the ordinary fixed source calculation for the unperturbed system. A set of perturbation particle is started at the collision point in the perturbed region and tracked until death. For a perturbation in a smaller portion of the whole domain, the efficiency of the perturbation source method can be improved by using a virtual scattering coefficient or cross section in the perturbed region, forcing collisions. Performance is evaluated by comparing the proposed method to other Monte Carlo perturbation methods. Numerical tests performed for a particle transport in a two-dimensional geometry reveal that the perturbation source method is less effective than the correlated sampling method for a perturbation in a larger portion of the whole domain. However, for a perturbation in a smaller portion, the perturbation source method outperforms the correlated sampling method. The efficiency depends strongly on the adjustment of the new virtual scattering coefficient or cross section.

  17. Improved PCR performance using template DNA from formalin-fixed and paraffin-embedded tissues by overcoming PCR inhibition.

    PubMed

    Dietrich, Dimo; Uhl, Barbara; Sailer, Verena; Holmes, Emily Eva; Jung, Maria; Meller, Sebastian; Kristiansen, Glen

    2013-01-01

    Formalin-fixed and paraffin-embedded (FFPE) tissues represent a valuable source for biomarker studies and clinical routine diagnostics. However, they suffer from degradation of nucleic acids due to the fixation process. Since genetic and epigenetic studies usually require PCR amplification, this degradation hampers its use significantly, impairing PCR robustness or necessitating short amplicons. In routine laboratory medicine a highly robust PCR performance is mandatory for the clinical utility of genetic and epigenetic biomarkers. Therefore, methods to improve PCR performance using DNA from FFPE tissue are highly desired and of wider interest. The effect of template DNA derived from FFPE tissues on PCR performance was investigated by means of qPCR and conventional PCR using PCR fragments of different sizes. DNA fragmentation was analyzed via agarose gel electrophoresis. This study showed that poor PCR amplification was partly caused by inhibition of the DNA polymerase by fragmented DNA from FFPE tissue and not only due to the absence of intact template molecules of sufficient integrity. This PCR inhibition was successfully minimized by increasing the polymerase concentration, dNTP concentration and PCR elongation time thereby allowing for the robust amplification of larger amplicons. This was shown for genomic template DNA as well as for bisulfite-converted template DNA required for DNA methylation analyses. In conclusion, PCR using DNA from FFPE tissue suffers from inhibition which can be alleviated by adaptation of the PCR conditions, therefore allowing for a significant improvement of PCR performance with regard to variability and the generation of larger amplicons. The presented solutions to overcome this PCR inhibition are of tremendous value for clinical chemistry and laboratory medicine.

  18. Current Work on Furnaces and Data Analysis to Improve the Uniformity and Noise Levels for Metal Fixed Points

    NASA Astrophysics Data System (ADS)

    Head, D. I.; Gray, J.; de Podesta, M.

    2009-02-01

    Ongoing work to improve the uniformity of vertically mounted furnaces, manufactured by Carbolite (e.g., Type TZF12/75—three-zone furnace capable of 1200 °C, with 75 mm inner bore) along the axis and across the working tube and/or equalizing block is reported. This involves adjusting the size of the end zones, the position of the control thermometers, and the use of cascade-control methods. Means regularly used at NPL to reduce electrical noise in some commercially available ac furnaces through a reduction in the voltage used to “fire” the heaters, and better use of thyristor controllers (by extending their cycle time) are described. The need to shield the controllers from local magnetic fields is described. With these measures, the electrical noise from ac furnaces can approach that of dc furnaces, without the large cost of a dc power supply. The application of new data analysis techniques (Allan deviation) will be shown to improve the representation of uninterrupted fixed-point traces (as used in ingot verification rather than PRT calibration). Reduction of statistical noise on the temperature measurements has been achieved for data on the freezing plateau by determining the statistically optimum averaging time. This shows that the statistical uncertainty in the determination of the temperature of a particular freezing plateau is less than 25 μK and that noise (drift) from other sources, possibly due to variations in room temperature, starts to become appreciable over periods longer than a few tens of minutes. The measurement of freezing and melting plateaux at this level is aided by the introduction of new ASL-F900 bridge(s), and quieter/larger standard resistor baths.

  19. Improved complementary polymer pair system: switching for enzyme activity by PEGylated polymers.

    PubMed

    Kurinomaru, Takaaki; Tomita, Shunsuke; Kudo, Shinpei; Ganguli, Sumon; Nagasaki, Yukio; Shiraki, Kentaro

    2012-03-06

    The development of technology for on/off switching of enzyme activity is expected to expand the applications of enzyme in a wide range of research fields. We have previously developed a complementary polymer pair system (CPPS) that enables the activity of several enzymes to be controlled by a pair of oppositely charged polymers. However, it failed to control the activity of large and unstable α-amylase because the aggregation of the complex between anionic α-amylase and cationic poly(allylamine) (PAA) induced irreversible denaturation of the enzyme. To address this issue, we herein designed and synthesized a cationic copolymer with a poly(ethylene glycol) backbone, poly(N,N-diethylaminoethyl methacrylate)-block-poly(ethylene glycol) (PEAMA-b-PEG). In contrast to PAA, α-amylase and β-galactosidase were inactivated by PEAMA-b-PEG with the formation of soluble complexes. The enzyme/PEAMA-b-PEG complexes were then successfully recovered from the complex by the addition of anionic poly(acrylic acid) (PAAc). Thus, dispersion of the complex by PEG segment in PEAMA-b-PEG clearly plays a crucial role for regulating the activities of these enzymes, suggesting that PEGylated charged polymer is a new candidate for CPPS for large and unstable enzymes.

  20. Utilizing multiple state variables to improve the dynamic range of analog switching in a memristor

    SciTech Connect

    Jeong, YeonJoo; Kim, Sungho; Lu, Wei D.

    2015-10-26

    Memristors and memristive systems have been extensively studied for data storage and computing applications such as neuromorphic systems. To act as synapses in neuromorphic systems, the memristor needs to exhibit analog resistive switching (RS) behavior with incremental conductance change. In this study, we show that the dynamic range of the analog RS behavior can be significantly enhanced in a tantalum-oxide-based memristor. By controlling different state variables enabled by different physical effects during the RS process, the gradual filament expansion stage can be selectively enhanced without strongly affecting the abrupt filament length growth stage. Detailed physics-based modeling further verified the observed experimental effects and revealed the roles of oxygen vacancy drift and diffusion processes, and how the diffusion process can be selectively enhanced during the filament expansion stage. These findings lead to more desirable and reliable memristor behaviors for analog computing applications. Additionally, the ability to selectively control different internal physical processes demonstrated in the current study provides guidance for continued device optimization of memristor devices in general.

  1. Improved performance of thermal-optic switch using polymer/silica hybrid and air trench waveguide structures.

    PubMed

    Liu, Yu-Fen; Wang, Xi-Bin; Sun, Jing-Wen; Sun, Jian; Wang, Fei; Chen, Chang-Ming; Sun, Xiao-Qiang; Cui, Zhan-Chen; Zhang, Da-Ming

    2015-05-01

    By exploiting the polymer/silica hybrid and the air trench waveguide structures, we demonstrate a new type of low-power consuming and high-speed thermal-optic (TO) switch. Such a design provides an effective means to shorten the switching time of the TO switches, as well as to reduce the power consumption at the same time. This TO switch operated with less than 150 μs of switching time via a polymer/silica hybrid waveguide structure. Meanwhile, the power consumption was reduced to be 3.4 mW by introducing the air trench structure.

  2. Improved uniformity in the switching characteristics of ZnO-based memristors using Ti sub-oxide layers

    NASA Astrophysics Data System (ADS)

    Park, Ju Hyun; Jeon, Dong Su; Kim, Tae Geun

    2017-01-01

    In this paper, improved uniformity in the resistive switching (RS) characteristics of ZnO-based memristors using Ti sub-oxide layers (metallic TiO x , insulating TiO y ) is reported. Compared with Pt/Ti/ZnO/Pt cells, more reliable and reproducible RS operation was observed in Pt/TiO x (or TiO y )/ZnO/Pt cells, particularly with insulating TiO y , because Ti sub-oxide layers play the role of oxygen reservoirs that help rupture the conducting filament. By comparison, Pt/TiO y /ZnO/Pt cells exhibited the best performance, with a large on/off ratio (~105) at a read voltage of 0.4 V, and highly stable low- and high-resistive state operation for 100 direct-current sweep cycles.

  3. Reduction in write error rate of voltage-driven dynamic magnetization switching by improving thermal stability factor

    NASA Astrophysics Data System (ADS)

    Shiota, Yoichi; Nozaki, Takayuki; Tamaru, Shingo; Yakushiji, Kay; Kubota, Hitoshi; Fukushima, Akio; Yuasa, Shinji; Suzuki, Yoshishige

    2017-07-01

    In this study, we demonstrate voltage-driven dynamic magnetization switching for the write error rate (WER) of the order of 10-5. The largest voltage effect on the perpendicular magnetic anisotropy in Ta/(CoxFe100-x)80B20/MgO structure (x = 0, 10, 31, 51) is obtained for x = 31 after annealing at 250 °C. Based on investigations using perpendicularly magnetized magnetic tunnel junctions that have different (Co31Fe69)80B20 free layer thicknesses, we demonstrate that the improvement in the thermal stability factor is important to reduce the WER. Our results will facilitate the design of highly reliable, voltage-torque, magnetoresistive random access memory.

  4. Dual referenced composite free layer design optimization for improving switching efficiency of spin-transfer torque RAM

    NASA Astrophysics Data System (ADS)

    Bell, Roy; Hu, Jiaxi; Victora, R. H.

    2017-05-01

    We present a detailed numerical analysis of switching efficiency for the recently proposed dual referenced composite free layer structure with respect to Gilbert damping. Low anisotropy assistive layers enable reduction of Gilbert damping and an increase of partial spin polarization within those low anisotropy layers—not feasible with single layer structures that require high anisotropy for thermal stability. When the damping of the soft layers is ultra-low, an efficiency (kBT /μ A ) of 8.1 is achieved for the composite structure with perpendicular anisotropy. This represents an improvement of 286% and 913% relative to the state-of-the-art dual-referenced and conventional STT-RAM cells, respectively. Results for structures with longitudinal anisotropy are also presented. A linear calculation of the STT polarization pre-factor is also described that captures all reflections.

  5. Improving Power Quality and Distribution Efficiency in Micro-Grids by Plug & Play Control of Switching Power Interfaces

    NASA Astrophysics Data System (ADS)

    Tenti, Paolo; Costabeber, Alessandro; Mattavelli, Paolo

    Smart grids offer a wide application domain for power electronics. In fact, every distributed generator (DG) includes an electronic power processor (Switching Power Interface, SPI) which controls the currents drawn from the grid and can be driven to optimize the power flow, improve voltage stability and increase distribution efficiency. For these aims, such distributed SPIs must perform cooperatively. This is true also in low-voltage residential micro-grids, where the number of active DGs and the generated power may vary during daytime, thus requiring dynamic adaptation of SPI operation. To achieve this goal different approaches can be adopted, depending on the available communication capability. This paper discusses various control solutions applicable in absence of supervisory control, e. g., in residential micro-grids, where communication is possible between neighbor units only (surround control) or is not available at all (plug & play control).

  6. MOSFET solid state switching circuit improves the 0 to 99% rise time for framing camera deflection electronics

    SciTech Connect

    Rivera, A.T.; Thomas, S.

    1996-09-01

    We have improved the 0 to 99% rise time voltage on our 2 frame deflection plates from 160 to 65 nS with the addition of a peaking circuit that works in conjunction with our primary 2 frame deflection circuitry. Our peaking technique has applications to other HV pulsers including those which must drive 51 ohm loads. Generally, rise time voltages are measured between 10 and 90%. To minimize the camera image blur resulting from the dynamic influence of deflection plate potentials acting on photocathode electrons, it was necessary to design a circuit that would rise from 0 to the 99% voltage level in under 100nS. Once this voltage was reached, it was necessary to stay within 1% of the attained voltage level for a duration of 1 uS. This was accomplished with the use of MOSFET solid state switching.

  7. Switching from cyclosporine to tacrolimus leads to improved disease-specific quality of life in patients after kidney transplantation.

    PubMed

    Franke, G H; Trampenau, C; Reimer, J

    2006-06-01

    Advances in transplantation medicine are linked to improved efficacy of immunosuppressive agents. At the same time, these agents endanger medical success by side effects that may impair survival and quality of life (QOL). This study examined whether conversion to tacrolimus-based immunosuppression due to cyclosporine-related side effects improved. QOL in patients after kidney transplantation. In total 64 patients (29 men) with an average age of 51 years (SD+/-12) who had received a kidney allograft an average of 5.6 years (SD+/-4) before conversion participated. The reasons for conversion were cardiovascular/metabolic (n=26) or periodontal/dermatological side effects (n=38) of cyclosporine therapy. QOL was assessed before conversion and in average 7 months thereafter by a global (SF-36) and a disease-specific instrument (ESRD-SCL). Disease-specific QOL (ESRD-SCL, global index) improved significantly (P<.001, explanation of variance [EV]=16.6%) after conversion from cyclosporine to tacrolimus. In detail, cardiac and renal dysfunction (P<.01, EV=12.9%) as well as increased growth of gum and hair (P<.0001, EV=53.2%) were significantly reduced at end of the study. However, global QOL (SF-36) remained unchanged. Regardless of the indication (cardiovascular or cosmetic), switching to tacrolimus due to cyclosporine-related side effects improved disease-specific QOL within the short term.

  8. The effect of using mobile applications for improving oral hygiene in patients with orthodontic fixed appliances: a randomised controlled trial.

    PubMed

    Alkadhi, Omar H; Zahid, Mohammed N; Almanea, Read S; Althaqeb, Husam K; Alharbi, Turki H; Ajwa, Nancy M

    2017-07-13

    To investigate the effect of using mobile applications active reminders to improve oral hygiene in comparison to verbal oral hygiene instructions. Two-arm parallel randomised controlled trial. orthodontic clinics at two branches of a university hospitals of the college of dentistry of Riyadh Colleges of Dentistry and Pharmacy, Riyadh, Saudi Arabia. Forty-four 12-year-old and older subjects. Subjects undergoing orthodontic treatment with fixed appliances were randomly assigned to one of two groups using simple randomisation. Group I: subjects received a mobile application that sends active reminders of oral hygiene three times a day (n = 22). Group II: subjects received verbal oral hygiene instructions verbally during their routine orthodontic visits (n = 22). Two primary outcomes were assessed using plaque index (PI) and gingival index (GI) for Ramfjord teeth to evaluate the level of oral hygiene at baseline and after 4 weeks. Mean differences for PI and GI for group I were reduced from T1 to T2 (P < 0.05, P < 0.05) but did not significantly change for group II (P > 0.05, P > 0.05). Both PI and GI significantly reduced for group I compared to group II between T1 and T2 (P < 0.05, P < 0.05). PI and GI all significantly decreased after 4 weeks of using active reminders of oral hygiene instructions on mobile application compared to verbal oral hygiene instructions. The study was registered at clinicaltrials.gov with number: NCT03109769.

  9. Elevated Pressure Improves the Extraction and Identification of Proteins Recovered from Formalin-Fixed, Paraffin-Embedded Tissue Surrogates

    PubMed Central

    Fowler, Carol B.; Chesnick, Ingrid E.; Moore, Cedric D.; O'Leary, Timothy J.; Mason, Jeffrey T.

    2010-01-01

    Background Proteomic studies of formalin-fixed paraffin-embedded (FFPE) tissues are frustrated by the inability to extract proteins from archival tissue in a form suitable for analysis by 2-D gel electrophoresis or mass spectrometry. This inability arises from the difficulty of reversing formaldehyde-induced protein adducts and cross-links within FFPE tissues. We previously reported the use of elevated hydrostatic pressure as a method for efficient protein recovery from a hen egg-white lysozyme tissue surrogate, a model system developed to study formalin fixation and histochemical processing. Principal Findings In this study, we demonstrate the utility of elevated hydrostatic pressure as a method for efficient protein recovery from FFPE mouse liver tissue and a complex multi-protein FFPE tissue surrogate comprised of hen egg-white lysozyme, bovine carbonic anhydrase, bovine ribonuclease A, bovine serum albumin, and equine myoglobin (55∶15∶15∶10∶5 wt%). Mass spectrometry of the FFPE tissue surrogates retrieved under elevated pressure showed that both the low and high-abundance proteins were identified with sequence coverage comparable to that of the surrogate mixture prior to formaldehyde treatment. In contrast, non-pressure-extracted tissue surrogate samples yielded few positive and many false peptide identifications. Studies with soluble formalin-treated bovine ribonuclease A demonstrated that pressure modestly inhibited the rate of reversal (hydrolysis) of formaldehyde-induced protein cross-links. Dynamic light scattering studies suggest that elevated hydrostatic pressure and heat facilitate the recovery of proteins free of formaldehyde adducts and cross-links by promoting protein unfolding and hydration with a concomitant reduction in the average size of the protein aggregates. Conclusions These studies demonstrate that elevated hydrostatic pressure treatment is a promising approach for improving the recovery of proteins from FFPE tissues in a form

  10. Compound semiconductor optical waveguide switch

    DOEpatents

    Spahn, Olga B.; Sullivan, Charles T.; Garcia, Ernest J.

    2003-06-10

    An optical waveguide switch is disclosed which is formed from III-V compound semiconductors and which has a moveable optical waveguide with a cantilevered portion that can be bent laterally by an integral electrostatic actuator to route an optical signal (i.e. light) between the moveable optical waveguide and one of a plurality of fixed optical waveguides. A plurality of optical waveguide switches can be formed on a common substrate and interconnected to form an optical switching network.

  11. Improvement of endothelial function after switching previously treated HIV-infected patients to an NRTI-sparing bitherapy with maraviroc.

    PubMed

    Bernal, Enrique; Verdú, Jose Miguel Gomez; Vera, Francisco; Martinez, Onofre; Bravo, Joaquin; Galera, Carlos; Muñoz, Angeles; Garcia, Eva; Serrano, Jose; Perez, Ana; Vera, Carmen; Marín, Irene; Cano, Alfredo

    2014-01-01

    Nucleoside reverse transcriptase inhibitor (NRTI) is associated with endothelial dysfunction and proinflammatory effects. Maraviroc (MVC) is an antagonist of CCR5 receptor. CCR5 is the receptor of RANTES (Regulated on Activation, Normal T Cell Expressed and Secreted), a mediator of chronic inflammation and endothelial function. Our aim was to evaluate the maintenance of viral suppression and improvement of endothelial function in virologically suppressed HIV-infected patients switched to an NRTI-sparing combined antiretroviral therapy (cART) with MVC. This observational, non-interventional, multicenter study was performed at the Infectious Diseases Service of Santa Lucia, Morales Meseguer, Virgen de la Arrixaca and Reina Sofía University Hospital (Murcia, Spain). The selection criteria were to be asymptomatic on a regimen with undetectable viral load (<50 HIV-RNA copies/mL) for at least six months, no previous treatment with R5 antagonists, no evidence of previous protease inhibitor (PI) failure and available R5 tropism test. Twenty-one HIV-infected patients were selected after the treatment regimen was changed to Maraviroc 150 mg/once daily plus ritonavir-boosted PI therapy. Endothelial function was prospectively evaluated through flow-mediated dilatation (FMD) of the brachial artery at baseline and at weeks 24. We included 21 patients on treatment with PI in combination with 2 NRTI. The mean cART exposition was 133±68.9 months. Fourteen (66.6%) were males, aged 49±9 years, 15 (71.4%) smokers, 4 (19.04%) family history of coronary heart disease, 1 (5.76%) type 2 diabetes and 3 (14.28%) hypertensive, mean total cholesterol was 185.5±35 mg/dL, c-LDL 100.2±37 mg/dL, tryglicerides 170.42±92.03 mg/dL, cHDL 52.6±15.5 mg/dL, CD4 779,5±383.28 cells/mL, nadir CD4 187,96±96 cells/mL. After 24 weeks of follow-up of a switch to an NRTI-sparing regimen, 95.2% of HIV-patients on viral suppressive cART maintained viral suppression and CD4+ T cell count. This cART switch

  12. Improvement of endothelial function after switching previously treated HIV-infected patients to an NRTI-sparing bitherapy with maraviroc

    PubMed Central

    Bernal, Enrique; Miguel Gomez Verdú, Jose; Vera, Francisco; Martinez, Onofre; Bravo, Joaquin; Galera, Carlos; Muñoz, Angeles; Garcia, Eva; Serrano, Jose; Perez, Ana; Vera, Carmen; Marín, Irene; Cano, Alfredo

    2014-01-01

    Introduction Nucleoside reverse transcriptase inhibitor (NRTI) is associated with endothelial dysfunction and proinflammatory effects. Maraviroc (MVC) is an antagonist of CCR5 receptor. CCR5 is the receptor of RANTES (Regulated on Activation, Normal T Cell Expressed and Secreted), a mediator of chronic inflammation and endothelial function. Our aim was to evaluate the maintenance of viral suppression and improvement of endothelial function in virologically suppressed HIV-infected patients switched to an NRTI-sparing combined antiretroviral therapy (cART) with MVC. Materials and Methods This observational, non-interventional, multicenter study was performed at the Infectious Diseases Service of Santa Lucia, Morales Meseguer, Virgen de la Arrixaca and Reina Sofía University Hospital (Murcia, Spain). The selection criteria were to be asymptomatic on a regimen with undetectable viral load (<50 HIV-RNA copies/mL) for at least six months, no previous treatment with R5 antagonists, no evidence of previous protease inhibitor (PI) failure and available R5 tropism test. Twenty-one HIV-infected patients were selected after the treatment regimen was changed to Maraviroc 150 mg/once daily plus ritonavir-boosted PI therapy. Endothelial function was prospectively evaluated through flow-mediated dilatation (FMD) of the brachial artery at baseline and at weeks 24. Results We included 21 patients on treatment with PI in combination with 2 NRTI. The mean cART exposition was 133±68.9 months. Fourteen (66.6%) were males, aged 49±9 years, 15 (71.4%) smokers, 4 (19.04%) family history of coronary heart disease, 1 (5.76%) type 2 diabetes and 3 (14.28%) hypertensive, mean total cholesterol was 185.5±35 mg/dL, c-LDL 100.2±37 mg/dL, tryglicerides 170.42±92.03 mg/dL, cHDL 52.6±15.5 mg/dL, CD4 779,5±383.28 cells/mL, nadir CD4 187,96±96 cells/mL. After 24 weeks of follow-up of a switch to an NRTI-sparing regimen, 95.2% of HIV-patients on viral suppressive cART maintained viral

  13. Correlation between changes in quality of life and symptomatic improvement in Chinese patients switched from typical antipsychotics to olanzapine

    PubMed Central

    Montgomery, William; Kadziola, Zbigniew; Ye, Wenye; Xue, Hai Bo; Liu, Li; Treuer, Tamás

    2015-01-01

    Purpose The aim of this study was to investigate the correlation between changes in symptoms and changes in self-reported quality of life among Chinese patients with schizophrenia who were switched from a typical antipsychotic to olanzapine during usual outpatient care. Patients and methods This post hoc analysis was conducted using data from the Chinese subgroup (n=475) of a multicountry, 12-month, prospective, noninterventional, observational study. The primary publication previously reported the efficacy, safety, and quality of life among patients who switched from a typical antipsychotic to olanzapine. Patients with schizophrenia were included if their symptoms were inadequately controlled with a typical antipsychotic and they were switched to olanzapine. Symptom severity was measured using the Brief Psychiatric Rating Scale (BPRS) and the Clinical Global Impressions-Severity scale (CGI-S). Health-Related Quality of Life (HRQOL) was assessed using the World Health Organization Quality of Life–Abbreviated (WHOQOL-BREF). Paired t-tests were performed to assess changes from baseline to endpoint. Pearson’s correlation coefficients (r) were used to assess the correlations between change in symptoms (BPRS and CGI-S scores) and change in HRQOL (WHOQOL-BREF scores). Results Symptoms and HRQOL both improved significantly over the 12 months of treatment (P<0.001). Significant correlations were observed between changes from baseline to end of study on the BPRS and the CGI-S and each of the WHOQOL-BREF four domain scores and two overall quality-of-life questions. The correlation coefficients ranged from r=−0.45 to r=−0.53 for the BPRS and WHOQOL-BREF. The correlation coefficients were slightly smaller between the CGI-S and WHOQOL-BREF, ranging from r=−0.33 to r=−0.40. Conclusion For patients with schizophrenia, assessing quality of life has the potential to add valuable information to the clinical assessment that takes into account the patient’s own

  14. Switching from zidovudine/lamivudine to tenofovir/emtricitabine improves fat distribution as measured by fat mass ratio.

    PubMed

    Martínez, E; Ribera, E; Clotet, B; Estrada, V; Sanz, J; Berenguer, J; Rubio, R; Pulido, F; Larrousse, M; Curran, A; Negredo, E; Arterburn, S; Ferrer, P; Álvarez, M L

    2015-07-01

    Fat mass ratio (FMR) has been suggested as an objective indicator of abnormal body fat distribution in HIV infection. Although it could provide more comprehensive information on body fat changes than limb fat mass, FMR has scarcely been used in clinical trials examining body fat distribution in HIV-infected patients. A subanalysis of a controlled, randomized clinical trial in virologically suppressed HIV-1-infected men switching from zidovudine (ZDV)/lamivudine (3TC) to emtricitabine (FTC)/tenofovir (TDF) versus continuing on ZDV/3TC was carried out. FMR was assessed by dual X-ray absorptiometry (DEXA) for a period of 72 weeks. Lipoatrophy was defined as FMR ≥ 1.5. Multivariate linear regression models for the change in FMR from baseline were fitted. Sixty-five men were randomized and treated (28 in the FTC/TDF arm and 37 in the ZDV/3TC arm), and 57 completed the study (25 and 32 in each arm, respectively). In the FTC/TDF arm, adjusted mean FMR decreased by 0.52 at week 72 (P = 0.014), and in the ZDV/3TC arm it increased by 0.13 (P = 0.491; P between arms = 0.023). Among subjects with lipoatrophy (baseline FMR ≥ 1.5), adjusted FMR decreased by 0.76 (P = 0.003) in the FTC/TDF arm and increased by 0.21 (P = 0.411; P between arms = 0.009) in the ZDV/3TC arm. Baseline FMR and treatment group were significant predictors (P < 0.05) of post-baseline changes in FMR. Switching from ZDV/3TC to FTC/TDF led to an improvement in FMR, compared with progressive worsening of FMR in subjects receiving ZDV/3TC, showing that fat mass not only increased but was also distributed in a healthier way after the switch. © 2014 British HIV Association.

  15. Study of optoelectronic switch for satellite-switched time-division multiple access

    NASA Technical Reports Server (NTRS)

    Su, Shing-Fong; Jou, Liz; Lenart, Joe

    1987-01-01

    The use of optoelectronic switching for satellite switched time division multiple access will improve the isolation and reduce the crosstalk of an IF switch matrix. The results are presented of a study on optoelectronic switching. Tasks include literature search, system requirements study, candidate switching architecture analysis, and switch model optimization. The results show that the power divided and crossbar switching architectures are good candidates for an IF switch matrix.

  16. Highly improved resistive switching performances of the self-doped Pt/HfO2:Cu/Cu devices by atomic layer deposition

    NASA Astrophysics Data System (ADS)

    Liu, Sen; Wang, Wei; Li, QingJiang; Zhao, XiaoLong; Li, Nan; Xu, Hui; Liu, Qi; Liu, Ming

    2016-12-01

    Metal-oxide electrochemical metallization (ECM) memory is a promising candidate for the next generation nonvolatile memory. But this memory suffers from large dispersion of resistive switching parameters due to the intrinsic randomness of the conductive filament. In this work, we have proposed a self-doping approach to improve the resistive switching characteristics. The fabricated Pt/HfO2:Cu/Cu device shows outstanding nonvolatile memory properties, including high uniformity, good endurance, long retention and fast switching speed. The results demonstrate that the self-doping approach is an effective method to improve the metal-oxide ECM memory performances and the self-doped Pt/HfO2:Cu/Cu device has high potentiality for the nonvolatile memory applications in the future.

  17. Strategies to improve fertility in Bos indicus postpubertal heifers and nonlactating cows submitted to fixed-time artificial insemination.

    PubMed

    Peres, R F G; Claro, I; Sá Filho, O G; Nogueira, G P; Vasconcelos, J L M

    2009-09-15

    Two experiments were designed to evaluate strategies to increase fertility of Bos indicus postpubertal heifers and nonlactating cows submitted to a fixed-time artificial insemination (TAI) protocol consisting of an intravaginal device containing 1.9 g of progesterone (CIDR) insertion+estradiol benzoate on Day 0, CIDR withdrawal+estradiol cypionate on Day 9, and TAI on Day 11. In Experiment 1, heifers (n=1153) received a new or an 18-d previously used CIDR and, on Day 9, prostaglandin F(2 alpha) (PGF(2 alpha))+0, 200, or 300 IU equine chorionic gonadotropin (eCG). Heifers treated with a new CIDR had greater (least squares means+/-SEM) serum concentration of progesterone on Day 9 (3.06+/-0.09 ng/mL vs. 2.53+/-0.09 ng/mL; P<0.05) and a smaller follicle at TAI (11.61+/-0.11 mm vs. 12.05+/-0.12 mm; P<0.05). Heifers with smaller follicles at TAI had lesser serum progesterone concentrations on Day 18 and reduced rates of ovulation, conception, and pregnancy (P<0.05). Treatment with eCG improved (P<0.05) follicle diameter at TAI (11.50+/-0.10mm, 11.90+/-0.11 mm, and 12.00+/-0.10mm for 0, 100, and 200 IU, respectively), serum progesterone concentration on Day 18 (2.77+/-0.11 ng/mL, 3.81+/-0.11 ng/mL, and 4.87+/-0.11 ng/mL), and rates of ovulation (83.8%, 88.5%, and 94.3%) and pregnancy (41.3%, 47.0%, and 46.7%). In Experiment 2, nonlactating Nelore cows (n=702) received PGF(2 alpha) treatment on Days 7 or 9 and, on Day 9, 0 or 300 IU eCG. Cows receiving PGF(2 alpha) on Day 7 had lesser serum progesterone concentrations on Day 9 (3.05+/-0.21 ng/mL vs. 4.58+/-0.21 ng/mL; P<0.05), a larger follicle at TAI (11.54+/-0.21 mm vs. 10.84+/-0.21 mm; P<0.05), and improved (P<0.05) rates of ovulation (85.4% vs. 77.0%), conception (60.9% vs. 47.2%), and pregnancy (52.0% vs. 36.4%). Treatment with eCG improved (P<0.05) serum progesterone concentration on Day 18 (3.24+/-0.14 ng/mL vs. 4.55+/-0.14 ng/mL) and the rates of ovulation (72.4% vs. 90.0%) and pregnancy (37.5% vs. 50.8%). In

  18. Switching to letrozole or exemestane improves hot flushes, mood and quality of life in tamoxifen intolerant women

    PubMed Central

    Thomas, R; Williams, M; Marshall, C; Walker, L

    2008-01-01

    We report an open-label, prospective, crossover study involving 184 post-menopausal women experiencing hot flushes on adjuvant tamoxifen (T). Six weeks after switching to an AI, the primary end point, hot flush score, improved by 47.3% (P<0.001) compared to those reported on T. The mean mood rating scale (MRS) score improved by 9.7% (P=0.01). The total mean combined FACT (b+es) score improved from 134.2 (95% CI ±2.96) to 143.5 (95% CI ±2.96 <0.001), and the endocrine subscale improved by 9.8% from 51.73 (95% CI ±1.38) to 57.34 (CI ±1.38, P<0.001). At 6 weeks, significantly more women chose to remain on an AI: 133 (72%), vs 40 (22%) (P<0.001) preferring T. At 3 months, 107 (58%) preferred to remain on an AI, 55(30%) on T, and 22 (12%) withdrew. The overall arthralgia rate at 3 months was 47% on AI and 30% on T (P=0.001). In all 182 (99%) women reported appreciating the opportunity to experience both drugs. These data suggest that if patients suffering significant adverse effects on T are given the opportunity to try an AI, this empowers them to prioritise relative side-effects, improving wellbeing in a significant proportion. These data also highlight the need for hospital follow-up in this intolerant cohort. PMID:18392053

  19. HIV pill reminder device shows some adherence improvement. Technology now switched to cell phone.

    PubMed

    2005-12-01

    Researchers studying a population of HIV patients found that a pill reminder improved adherence for those who were memory impaired. "One reason patients don't take medications is because they simply forget it, and it's more of an issue in the population we studied because some started with mild cognitive impairment," says Adriana Andrade, MD, MPH, an assistant professor at Johns Hopkins University Division of Infectious Diseases in Baltimore, MD.

  20. Akt inhibition improves irinotecan treatment and prevents cell emergence by switching the senescence response to apoptosis

    PubMed Central

    Vétillard, Alexandra; Jonchère, Barbara; Moreau, Marie; Toutain, Bertrand; Henry, Cécile; Fontanel, Simon; Bernard, Anne-Charlotte; Campone, Mario; Guette, Catherine; Coqueret, Olivier

    2015-01-01

    Activated in response to chemotherapy, senescence is a tumor suppressive mechanism that induces a permanent loss of proliferation. However, in response to treatment, it is not really known how cells can escape senescence and how irreversible or incomplete this pathway is. We have recently described that cells that escape senescence are more transformed than non-treated parental cells, they resist anoikis and rely on Mcl-1. In this study, we further characterize this emergence in response to irinotecan, a first line treatment used in colorectal cancer. Our results indicate that Akt was activated as a feedback pathway during the early step of senescence. The inhibition of the kinase prevented cell emergence and improved treatment efficacy, both in vitro and in vivo. This improvement was correlated with senescence inhibition, p21waf1 downregulation and a concomitant activation of apoptosis due to Noxa upregulation and Mcl-1 inactivation. The inactivation of Noxa prevented apoptosis and increased the number of emergent cells. Using either RNA interference or p21waf1-deficient cells, we further confirmed that an intact p53-p21-senescence pathway favored cell emergence and that its downregulation improved treatment efficacy through apoptosis induction. Therefore, although senescence is an efficient suppressive mechanism, it also generates more aggressive cells as a consequence of apoptosis inhibition. We therefore propose that senescence-inducing therapies should be used sequentially with drugs favoring cell death such as Akt inhibitors. This should reduce cell emergence and tumor relapse through a combined induction of senescence and apoptosis. PMID:26485768

  1. Control bandwidth improvements in GRAVITY fringe tracker by switching to a synchronous real time computer architecture

    NASA Astrophysics Data System (ADS)

    Abuter, Roberto; Dembet, Roderick; Lacour, Sylvestre; di Lieto, Nicola; Woillez, Julien; Eisenhauer, Frank; Fedou, Pierre; Phan Duc, Than

    2016-08-01

    The new VLTI (Very Large Telescope Interferometer) 1 instrument GRAVITY5, 22, 23 is equipped with a fringe tracker16 able to stabilize the K-band fringes on six baselines at the same time. It has been designed to achieve a performance for average seeing conditions of a residual OPD (Optical Path Difference) lower than 300 nm with objects brighter than K = 10. The control loop implementing the tracking is composed of a four stage real time computer system compromising: a sensor where the detector pixels are read in and the OPD and GD (Group Delay) are calculated; a controller receiving the computed sensor quantities and producing commands for the piezo actuators; a concentrator which combines both the OPD commands with the real time tip/tilt corrections offloading them to the piezo actuator; and finally a Kalman15 parameter estimator. This last stage is used to monitor current measurements over a window of few seconds and estimate new values for the main Kalman15 control loop parameters. The hardware and software implementation of this design runs asynchronously and communicates the four computers for data transfer via the Reflective Memory Network3. With the purpose of improving the performance of the GRAVITY5, 23 fringe tracking16, 22 control loop, a deviation from the standard asynchronous communication mechanism has been proposed and implemented. This new scheme operates the four independent real time computers involved in the tracking loop synchronously using the Reflective Memory Interrupts2 as the coordination signal. This synchronous mechanism had the effect of reducing the total pure delay of the loop from 3.5 [ms] to 2.0 [ms] which then translates on a better stabilization of the fringes as the bandwidth of the system is substantially improved. This paper will explain in detail the real time architecture of the fringe tracker in both is synchronous and synchronous implementation. The achieved improvements on reducing the delay via this mechanism will be

  2. Universally improving effect of mixed electron donors on the CO₂ fixing efficiency of non-photosynthetic microbial communities from marine environments.

    PubMed

    Hu, Jiajun; Wang, Lei; Zhang, Shiping; Wang, Yuanqing; Jin, Fangming; Fu, Xiaohua; Li, Huirong

    2014-08-01

    The universality of improved CO₂ fixing upon the addition of mixed electron donors (MEDs) composed of Na₂S, NO₂(-), and S₂O₃(2-) to non-photosynthetic microbial communities (NPMCs) obtained from 12 locations in four oceans of the world was validated. The CO₂ fixing efficiencies of NPMCs were universally enhanced by MED compared with those obtained using H₂ alone as electron donor, with average increase of about 276%. An increase in microbial inoculation concentration could increase the net amount of CO₂ fixing to 853.34 mg/L in the presence of MED. NO₂(-) and S₂O₃(2-) may play the roles of both electron acceptor and electron donor under aerobic conditions, which may improve the energy utilization efficiency of NPMC and enhance the CO₂ fixation efficiency. The sequence determination of 16S ribosomal deoxyribonucleic acid (rDNA) from 150 bacteria of NPMC showed that more than 50% of the bacteria were symbiotic and there were many heterotrophic bacteria such as Vibrio natriegens. These results indicate that NPMC acts as a symbiotic CO₂ fixing system. The interaction between autotrophic and heterotrophic bacteria may be a crucial factor supporting ladder utilization and recycling of energy/carbon source.

  3. Switching harmful visceral fat to beneficial energy combustion improves metabolic dysfunctions

    PubMed Central

    Yang, Xiaoyan; Sui, Wenhai; Zhang, Meng; Dong, Mei; Lim, Sharon; Seki, Takahiro; Guo, Ziheng; Fischer, Carina; Lu, Huixia; Zhang, Cheng; Yang, Jianmin; Zhang, Meng; Wang, Yangang; Cao, Caixia; Gao, Yanyan; Zhao, Xingguo; Sun, Meili; Sun, Yuping; Zhuang, Rujie; Samani, Nilesh J.; Zhang, Yun

    2017-01-01

    Visceral fat is considered the genuine and harmful white adipose tissue (WAT) that is associated to development of metabolic disorders, cardiovascular disease, and cancer. Here, we present a new concept to turn the harmful visceral fat into a beneficial energy consumption depot, which is beneficial for improvement of metabolic dysfunctions in obese mice. We show that low temperature–dependent browning of visceral fat caused decreased adipose weight, total body weight, and body mass index, despite increased food intake. In high-fat diet–fed mice, low temperature exposure improved browning of visceral fat, global metabolism via nonshivering thermogenesis, insulin sensitivity, and hepatic steatosis. Genome-wide expression profiling showed upregulation of WAT browning–related genes including Cidea and Dio2. Conversely, Prdm16 was unchanged in healthy mice or was downregulated in obese mice. Surgical removal of visceral fat and genetic knockdown of UCP1 in epididymal fat largely ablated low temperature–increased global thermogenesis and resulted in the death of most mice. Thus, browning of visceral fat may be a compensatory heating mechanism that could provide a novel therapeutic strategy for treating visceral fat–associated obesity and diabetes. PMID:28239649

  4. Switching harmful visceral fat to beneficial energy combustion improves metabolic dysfunctions.

    PubMed

    Yang, Xiaoyan; Sui, Wenhai; Zhang, Meng; Dong, Mei; Lim, Sharon; Seki, Takahiro; Guo, Ziheng; Fischer, Carina; Lu, Huixia; Zhang, Cheng; Yang, Jianmin; Zhang, Meng; Wang, Yangang; Cao, Caixia; Gao, Yanyan; Zhao, Xingguo; Sun, Meili; Sun, Yuping; Zhuang, Rujie; Samani, Nilesh J; Zhang, Yun; Cao, Yihai

    2017-02-23

    Visceral fat is considered the genuine and harmful white adipose tissue (WAT) that is associated to development of metabolic disorders, cardiovascular disease, and cancer. Here, we present a new concept to turn the harmful visceral fat into a beneficial energy consumption depot, which is beneficial for improvement of metabolic dysfunctions in obese mice. We show that low temperature-dependent browning of visceral fat caused decreased adipose weight, total body weight, and body mass index, despite increased food intake. In high-fat diet-fed mice, low temperature exposure improved browning of visceral fat, global metabolism via nonshivering thermogenesis, insulin sensitivity, and hepatic steatosis. Genome-wide expression profiling showed upregulation of WAT browning-related genes including Cidea and Dio2. Conversely, Prdm16 was unchanged in healthy mice or was downregulated in obese mice. Surgical removal of visceral fat and genetic knockdown of UCP1 in epididymal fat largely ablated low temperature-increased global thermogenesis and resulted in the death of most mice. Thus, browning of visceral fat may be a compensatory heating mechanism that could provide a novel therapeutic strategy for treating visceral fat-associated obesity and diabetes.

  5. Real-Time DC-dynamic Biasing Method for Switching Time Improvement in Severely Underdamped Fringing-field Electrostatic MEMS Actuators

    PubMed Central

    Small, Joshua; Fruehling, Adam; Garg, Anurag; Liu, Xiaoguang; Peroulis, Dimitrios

    2014-01-01

    Mechanically underdamped electrostatic fringing-field MEMS actuators are well known for their fast switching operation in response to a unit step input bias voltage. However, the tradeoff for the improved switching performance is a relatively long settling time to reach each gap height in response to various applied voltages. Transient applied bias waveforms are employed to facilitate reduced switching times for electrostatic fringing-field MEMS actuators with high mechanical quality factors. Removing the underlying substrate of the fringing-field actuator creates the low mechanical damping environment necessary to effectively test the concept. The removal of the underlying substrate also a has substantial improvement on the reliability performance of the device in regards to failure due to stiction. Although DC-dynamic biasing is useful in improving settling time, the required slew rates for typical MEMS devices may place aggressive requirements on the charge pumps for fully-integrated on-chip designs. Additionally, there may be challenges integrating the substrate removal step into the back-end-of-line commercial CMOS processing steps. Experimental validation of fabricated actuators demonstrates an improvement of 50x in switching time when compared to conventional step biasing results. Compared to theoretical calculations, the experimental results are in good agreement. PMID:25145811

  6. Real-time DC-dynamic biasing method for switching time improvement in severely underdamped fringing-field electrostatic MEMS actuators.

    PubMed

    Small, Joshua; Fruehling, Adam; Garg, Anurag; Liu, Xiaoguang; Peroulis, Dimitrios

    2014-08-15

    Mechanically underdamped electrostatic fringing-field MEMS actuators are well known for their fast switching operation in response to a unit step input bias voltage. However, the tradeoff for the improved switching performance is a relatively long settling time to reach each gap height in response to various applied voltages. Transient applied bias waveforms are employed to facilitate reduced switching times for electrostatic fringing-field MEMS actuators with high mechanical quality factors. Removing the underlying substrate of the fringing-field actuator creates the low mechanical damping environment necessary to effectively test the concept. The removal of the underlying substrate also a has substantial improvement on the reliability performance of the device in regards to failure due to stiction. Although DC-dynamic biasing is useful in improving settling time, the required slew rates for typical MEMS devices may place aggressive requirements on the charge pumps for fully-integrated on-chip designs. Additionally, there may be challenges integrating the substrate removal step into the back-end-of-line commercial CMOS processing steps. Experimental validation of fabricated actuators demonstrates an improvement of 50x in switching time when compared to conventional step biasing results. Compared to theoretical calculations, the experimental results are in good agreement.

  7. Improvement of Bipolar Switching Properties of Gd:SiOx RRAM Devices on Indium Tin Oxide Electrode by Low-Temperature Supercritical CO2 Treatment.

    PubMed

    Chen, Kai-Huang; Chang, Kuan-Chang; Chang, Ting-Chang; Tsai, Tsung-Ming; Liang, Shu-Ping; Young, Tai-Fa; Syu, Yong-En; Sze, Simon M

    2016-12-01

    Bipolar switching resistance behaviors of the Gd:SiO2 resistive random access memory (RRAM) devices on indium tin oxide electrode by the low-temperature supercritical CO2-treated technology were investigated. For physical and electrical measurement results obtained, the improvement on oxygen qualities, properties of indium tin oxide electrode, and operation current of the Gd:SiO2 RRAM devices were also observed. In addition, the initial metallic filament-forming model analyses and conduction transferred mechanism in switching resistance properties of the RRAM devices were verified and explained. Finally, the electrical reliability and retention properties of the Gd:SiO2 RRAM devices for low-resistance state (LRS)/high-resistance state (HRS) in different switching cycles were also measured for applications in nonvolatile random memory devices.

  8. Improvement of Bipolar Switching Properties of Gd:SiOx RRAM Devices on Indium Tin Oxide Electrode by Low-Temperature Supercritical CO2 Treatment

    NASA Astrophysics Data System (ADS)

    Chen, Kai-Huang; Chang, Kuan-Chang; Chang, Ting-Chang; Tsai, Tsung-Ming; Liang, Shu-Ping; Young, Tai-Fa; Syu, Yong-En; Sze, Simon M.

    2016-02-01

    Bipolar switching resistance behaviors of the Gd:SiO2 resistive random access memory (RRAM) devices on indium tin oxide electrode by the low-temperature supercritical CO2-treated technology were investigated. For physical and electrical measurement results obtained, the improvement on oxygen qualities, properties of indium tin oxide electrode, and operation current of the Gd:SiO2 RRAM devices were also observed. In addition, the initial metallic filament-forming model analyses and conduction transferred mechanism in switching resistance properties of the RRAM devices were verified and explained. Finally, the electrical reliability and retention properties of the Gd:SiO2 RRAM devices for low-resistance state (LRS)/high-resistance state (HRS) in different switching cycles were also measured for applications in nonvolatile random memory devices.

  9. An analysis on how switching to a more balanced and naturally improved milk would affect consumer health and the environment.

    PubMed

    Roibás, Laura; Martínez, Ismael; Goris, Alfonso; Barreiro, Rocío; Hospido, Almudena

    2016-10-01

    This study compares a premium brand of UHT milk, Unicla, characterised by an improved nutritional composition, to conventional milk, in terms of health effects and environmental impacts. Unlike enriched milks, in which nutrients are added to the final product, Unicla is obtained naturally by improving the diet of the dairy cows. Health effects have been analysed based on literature findings, while the environmental analysis focused on those spheres of the environment where milk is expected to cause the higher impacts, and thus carbon (CF) and water footprints (WF) have been determined. Five final products have been compared: 3 conventional (skimmed, semi-skimmed, whole) and 2 Unicla (skimmed, semi-skimmed) milks. As a functional unit, one litre of packaged UHT milk entering the regional distribution centre has been chosen. The improved composition of Unicla milk is expected to decrease the risk of cardiovascular disease and to protect consumers against oxidative damage, among other health benefits. Concerning the environmental aspect, CF of Unicla products are, on average, 10% lower than their conventional equivalents, mainly due to the lower enteric emissions of caused by the Unicla diet. No significant differences were found between the WF of Unicla and conventional milk. Raw milk is the main contributor to both footprints (on average, 83.2 and 84.3% of the total CF of Unicla and conventional milk, respectively, and 99.9% of WF). The results have been compared to those found in literature, and a sensitivity analysis has been performed to verify their robustness. The study concludes that switching to healthier milk compositions can help slowing down global warming, without contributing to other environmental issues such as water scarcity. The results should encourage other milk companies to commit to the development of healthier, less environmentally damaging products, and also to stimulate consumers to bet on them.

  10. Partial spin absorption induced magnetization switching and its voltage-assisted improvement in an asymmetrical all spin logic device at the mesoscopic scale

    NASA Astrophysics Data System (ADS)

    Zhang, Yue; Zhang, Zhizhong; Wang, Lezhi; Nan, Jiang; Zheng, Zhenyi; Li, Xiang; Wong, Kin; Wang, Yu; Klein, Jacques-Olivier; Khalili Amiri, Pedram; Zhang, Youguang; Wang, Kang L.; Zhao, Weisheng

    2017-07-01

    Beyond memory and storage, future logic applications put forward higher requirements for electronic devices. All spin logic devices (ASLDs) have drawn exceptional interest as they utilize pure spin current instead of charge current, which could promise ultra-low power consumption. However, relatively low efficiencies of spin injection, transport, and detection actually impede high-speed magnetization switching and challenge perspectives of ASLD. In this work, we study partial spin absorption induced magnetization switching in asymmetrical ASLD at the mesoscopic scale, in which the injector and detector have the nano-fabrication compatible device size (>100 nm) and their contact areas are different. The enlarged contact area of the detector is conducive to the spin current absorption, and the contact resistance difference between the injector and the detector can decrease the spin current backflow. Rigorous spin circuit modeling and micromagnetic simulations have been carried out to analyze the electrical and magnetic features. The results show that, at the fabrication-oriented technology scale, the ferromagnetic layer can hardly be switched by geometrically partial spin current absorption. The voltage-controlled magnetic anisotropy (VCMA) effect has been applied on the detector to accelerate the magnetization switching by modulating magnetic anisotropy of the ferromagnetic layer. With a relatively high VCMA coefficient measured experimentally, a voltage of 1.68 V can assist the whole magnetization switching within 2.8 ns. This analysis and improving approach will be of significance for future low-power, high-speed logic applications.

  11. Formation polarity dependent improved resistive switching memory characteristics using nanoscale (1.3 nm) core-shell IrOx nano-dots

    PubMed Central

    2012-01-01

    Improved resistive switching memory characteristics by controlling the formation polarity in an IrOx/Al2O3/IrOx-ND/Al2O3/WOx/W structure have been investigated. High density of 1 × 1013/cm2 and small size of 1.3 nm in diameter of the IrOx nano-dots (NDs) have been observed by high-resolution transmission electron microscopy. The IrOx-NDs, Al2O3, and WOx layers are confirmed by X-ray photo-electron spectroscopy. Capacitance-voltage hysteresis characteristics show higher charge-trapping density in the IrOx-ND memory as compared to the pure Al2O3 devices. This suggests that the IrOx-ND device has more defect sites than that of the pure Al2O3 devices. Stable resistive switching characteristics under positive formation polarity on the IrOx electrode are observed, and the conducting filament is controlled by oxygen ion migration toward the Al2O3/IrOx top electrode interface. The switching mechanism is explained schematically based on our resistive switching parameters. The resistive switching random access memory (ReRAM) devices under positive formation polarity have an applicable resistance ratio of > 10 after extrapolation of 10 years data retention at 85°C and a long read endurance of 105 cycles. A large memory size of > 60 Tbit/sq in. can be realized in future for ReRAM device application. This study is not only important for improving the resistive switching memory performance but also help design other nanoscale high-density nonvolatile memory in future. PMID:22439604

  12. Improving the solubility of anti-LINGO-1 monoclonal antibody Li33 by isotype switching and targeted mutagenesis.

    PubMed

    Pepinsky, R Blake; Silvian, Laura; Berkowitz, Steven A; Farrington, Graham; Lugovskoy, Alexey; Walus, Lee; Eldredge, John; Capili, Allan; Mi, Sha; Graff, Christilyn; Garber, Ellen

    2010-05-01

    Monoclonal antibodies (Mabs) are a favorite drug platform of the biopharmaceutical industry. Currently, over 20 Mabs have been approved and several hundred others are in clinical trials. The anti-LINGO-1 Mab Li33 was selected from a large panel of antibodies by Fab phage display technology based on its extraordinary biological activity in promoting oligodendrocyte differentiation and myelination in vitro and in animal models of remyelination. However, the Li33 Fab had poor solubility when converted into a full antibody in an immunoglobulin G1 framework. A detailed analysis of the biochemical and structural features of the antibody revealed several possible reasons for its propensity to aggregate. Here, we successfully applied three molecular approaches (isotype switching, targeted mutagenesis of complementarity determining region residues, and glycosylation site insertion mutagenesis) to address the solubility problem. Through these efforts we were able to improve the solubility of the Li33 Mab from 0.3 mg/mL to >50 mg/mL and reduce aggregation to an acceptable level. These strategies can be readily applied to other proteins with solubility issues.

  13. Improving the solubility of anti-LINGO-1 monoclonal antibody Li33 by isotype switching and targeted mutagenesis

    SciTech Connect

    Pepinsky, R. Blake; Silvian, Laura; Berkowitz, Steven A.; Farrington, Graham; Lugovskoy, Alexey; Walus, Lee; Eldredge, John; Capili, Allan; Mi, Sha; Graff, Christilyn; Garber, Ellen

    2010-11-15

    Monoclonal antibodies (Mabs) are a favorite drug platform of the biopharmaceutical industry. Currently, over 20 Mabs have been approved and several hundred others are in clinical trials. The anti-LINGO-1 Mab Li33 was selected from a large panel of antibodies by Fab phage display technology based on its extraordinary biological activity in promoting oligodendrocyte differentiation and myelination in vitro and in animal models of remyelination. However, the Li33 Fab had poor solubility when converted into a full antibody in an immunoglobulin G1 framework. A detailed analysis of the biochemical and structural features of the antibody revealed several possible reasons for its propensity to aggregate. Here, we successfully applied three molecular approaches (isotype switching, targeted mutagenesis of complementarity determining region residues, and glycosylation site insertion mutagenesis) to address the solubility problem. Through these efforts we were able to improve the solubility of the Li33 Mab from 0.3 mg/mL to >50 mg/mL and reduce aggregation to an acceptable level. These strategies can be readily applied to other proteins with solubility issues.

  14. Remodeling of Oxidative Energy Metabolism by Galactose Improves Glucose Handling and Metabolic Switching in Human Skeletal Muscle Cells

    PubMed Central

    Kase, Eili Tranheim; Nikolić, Nataša; Bakke, Siril Skaret; Bogen, Kaja Kamilla; Aas, Vigdis; Thoresen, G. Hege; Rustan, Arild Christian

    2013-01-01

    Cultured human myotubes have a low mitochondrial oxidative potential. This study aims to remodel energy metabolism in myotubes by replacing glucose with galactose during growth and differentiation to ultimately examine the consequences for fatty acid and glucose metabolism. Exposure to galactose showed an increased [14C]oleic acid oxidation, whereas cellular uptake of oleic acid uptake was unchanged. On the other hand, both cellular uptake and oxidation of [14C]glucose increased in myotubes exposed to galactose. In the presence of the mitochondrial uncoupler carbonylcyanide p-trifluormethoxy-phenylhydrazone (FCCP) the reserve capacity for glucose oxidation was increased in cells grown with galactose. Staining and live imaging of the cells showed that myotubes exposed to galactose had a significant increase in mitochondrial and neutral lipid content. Suppressibility of fatty acid oxidation by acute addition of glucose was increased compared to cells grown in presence of glucose. In summary, we show that cells grown in galactose were more oxidative, had increased oxidative capacity and higher mitochondrial content, and showed an increased glucose handling. Interestingly, cells exposed to galactose showed an increased suppressibility of fatty acid metabolism. Thus, galactose improved glucose metabolism and metabolic switching of myotubes, representing a cell model that may be valuable for metabolic studies related to insulin resistance and disorders involving mitochondrial impairments. PMID:23560061

  15. Long-term health-related quality of life improvements among patients treated with lurasidone: results from the open-label extension of a switch trial in schizophrenia.

    PubMed

    Awad, George; Ng-Mak, Daisy; Rajagopalan, Krithika; Hsu, Jay; Pikalov, Andrei; Loebel, Antony

    2016-06-01

    Long-term improvement of health-related quality of life (HRQoL) in schizophrenia may improve adherence and reduce relapse and rehospitalization. This analysis examines long-term changes in HRQoL among patients with schizophrenia switched to lurasidone from other antipsychotics. Patients who completed an open-label 6-week switch study continued on lurasidone for an additional 24-weeks. HRQoL was measured using the self-reported Personal Evaluation of Transitions in Treatment (PETiT) scale and Short-Form 12 (SF-12) questionnaire. The PETiT assessed HRQoL via total and domain scores (adherence-related attitude and psychosocial functioning). The SF-12 assessed patients' mental and physical component summary scores (MCS and PCS). Mean changes from the initial baseline were calculated at extension baseline and extension endpoint using analysis of covariance models. Analyses were further stratified by prior antipsychotic medication and responder status; responders were defined as having a ≥20 % improvement in Positive and Negative Syndrome Scale during the first 6-weeks of treatment. The analysis included 144 patients with PETIT or SF-12 data who received ≥1 dose of lurasidone. Mean (standard deviation) PETiT total score improved significantly from 34.9 (9.3) at baseline to 39.5 (8.9) at extension baseline and 39.1 (9.0) at extension endpoint, representing improvements of 4.5 (7.9) and 5.1 (7.2) points, respectively (both p < 0.001). Significant improvements in adherence-related attitude and psychosocial functioning were observed at extension baseline and extension endpoint (all p < 0.001). Improvement in SF-12 MCS score was observed at extension baseline and endpoint, and PCS score at extension endpoint (all p < 0.01). Patients who switched from quetiapine and aripiprazole showed significant improvement of PETiT total score and adherence-related attitude at extension baseline and extension endpoint. In addition, patients who switched from quetiapine

  16. Comparison of channel assignment techniques for hybrid switching

    NASA Technical Reports Server (NTRS)

    Schwartz, M.; Kraimeche, B.

    1982-01-01

    The performance of four circuit-switched channel assignment strategies for use in a hybrid switch accommodating multiple users is analyzed and compared. Each scheme is associated with a fixed frame movable boundary TDM channel that multiplexes circuit-switched (CS) and packet-switched (PS) traffic. The performance measures used are blocking probability for the circuit-switched traffic and time delay for the packet-switched traffic.

  17. Improved bipolar resistive switching memory characteristics in Ge0.5Se0.5 solid electrolyte by using dispersed silver nanocrystals on bottom electrode.

    PubMed

    Kim, Jang-Han; Nam, Ki-Hyun; Hwang, Inchan; Cho, Won-Ju; Park, Byoungchoo; Chung, Hong-Bay

    2014-12-01

    Resistive switching random-access memory (ReRAM) devices based on chalcogenide solid electrolytes have recently become a promising candidate for future low-power nanoscale nonvolatile memory application. The resistive switching mechanism of ReRAM is based on the formation and rupture of conductive filament (CF) in the chalcogenide solid electrolyte layers. However, the random diffusion of metal ions makes it hard to control the CF formation, which is one of the major obstacles to improving device performance of ReRAM devices. We demonstrate the spin-coated metal nanocrystals (NCs) enhance the bipolar resistive switching (BRS) memory characteristics. Compared to the Ag/Ge0.5Se0.5/Pt structure, excellent resistive switching memory characteristics were obtained from the Ag/Ge0.5Se0.5/Ag NCs/Pt structure. Ag NCs improve the uniformity of resistance values and reduce the reset voltage and current. A stable DC endurance (> 100 cycles) and a high data retention (> 10(4) sec) were achieved by spin coating the Ag NCs on the Pt bottom electrode for ReRAMs.

  18. Improvement of stability and efficiency in diode-pumped passively Q-switched intracavity optical parametric oscillator with a monolithic cavity Improvement of stability and efficiency

    NASA Astrophysics Data System (ADS)

    Huang, J. Y.; Zhuang, W. Z.; Huang, Y. P.; Huang, Y. J.; Su, K. W.; Chen, Y. F.

    2012-07-01

    We improve the performance of intracavity optical parametric oscillator (IOPO) pumped by a diode-pumped Q-switched Nd:YVO4/Cr4+:YAG laser. The IOPO cavity is formed independently by a monolithic KTP crystal that the mirrors are directly deposited on top of the nonlinear crystal. We study the performances of this IOPO cavity with different reflectivity of the output coupler at 1.5 μm (Rs) of 80 and 50%. The average power of 1.5 μm is up to 3.3 W at the maximum pump power of 16.8 W for both cases. The diode-to-signal conversion efficiency is up to 20%, which is the highest one for IOPOs to our best knowledge. At the maximum pump power, the pulse energies are 41 μJ with the pulse width of 3 ns at a pulse repetition rate (PRR) of 80 kHz for Rs = 80% and 51 μJ with the pulse width of 1.2 ns at a PRR of 65 kHz for Rs = 50%, respectively. The pulse amplitude fluctuations in standard deviation are 2.6% for Rs = 80% and 4% for Rs = 50%, respectively.

  19. Comparison of Q-Switched 1064-nm Nd: YAG laser and fractional CO2 laser efficacies on improvement of atrophic facial acne scar.

    PubMed

    Asilian, Ali; Salimi, Elias; Faghihi, Gita; Dehghani, Farideh; Tajmirriahi, Nabet; Hosseini, Sayed Mohsen

    2011-09-01

    Acne scarring is treatable by a variety of modalities. Ablative carbon dioxide laser (ACL), while effective, is associated with undesirable side effect profiles. Newer modalities using the principles of fractional photothermolysis (FP) produce modest results than traditional carbon dioxide (CO(2)) lasers but with fewer side effects. A novel ablative CO(2) laser device use a technique called ablative fractional resurfacing (AFR), combines CO(2) ablation with a FP system. This study was conducted to compare the efficacy of Q-switched 1064-nm Nd: YAG laser and that of fractional CO(2) laser in the treatment of patients with moderate to severe acne scarring. Sixty four subjects with moderate to severe facial acne scars were divided randomly into two groups. Group A received Q-Switched 1064-nm Nd: YAG laser and group B received fractional CO(2) laser. Two groups underwent four session treatment with laser at one month intervals. Results were evaluated by patients based on subjective satisfaction and physicians' assessment and photo evaluation by two blinded dermatologists. Assessments were obtained at baseline and at three and six months after final treatment. Post-treatment side effects were mild and transient in both groups. According to subjective satisfaction (p = 0.01) and physicians' assessment (p < 0.001), fractional CO(2) laser was significantly more effective than Q- Switched 1064- nm Nd: YAG laser. Fractional CO2 laser has the most significant effect on the improvement of atrophic facial acne scars, compared with Q-Switched 1064-nm Nd: YAG laser.

  20. Switch wear leveling

    DOEpatents

    Wu, Hunter; Sealy, Kylee; Gilchrist, Aaron

    2015-09-01

    An apparatus for switch wear leveling includes a switching module that controls switching for two or more pairs of switches in a switching power converter. The switching module controls switches based on a duty cycle control technique and closes and opens each switch in a switching sequence. The pairs of switches connect to a positive and negative terminal of a DC voltage source. For a first switching sequence a first switch of a pair of switches has a higher switching power loss than a second switch of the pair of switches. The apparatus includes a switch rotation module that changes the switching sequence of the two or more pairs of switches from the first switching sequence to a second switching sequence. The second switch of a pair of switches has a higher switching power loss than the first switch of the pair of switches during the second switching sequence.

  1. On the systematic improvement of fixed-node diffusion quantum Monte Carlo energies using pair natural orbital CI guide functions

    NASA Astrophysics Data System (ADS)

    Lüchow, Arne; Fink, Reinhold F.

    2000-11-01

    While the diffusion quantum Monte Carlo method (DQMC) is capable, in principle, of calculating exact ground state energies, in practice the fixed-node (FN) approximation leads to node location errors which make FN-DQMC energies upper bounds. It is shown that the node location error can be reduced systematically and without prohibitive increase of computer time requirements by using nodes derived from pair natural orbital CI wave functions (PNO-CI). The reduction is demonstrated for the N atom and the molecules N2 and H2O. With the DQMC/PNOCI method, we obtain a variational energy of -109.520(3) H for the N2 molecule and -76.429(1) H for the ground state of the water molecule which is only 22 and 9 mH above the estimated nonrelativistic ground state energy, respectively.

  2. A New Protective Circuit to Improve Short-Circuit Withstanding Capability of a Lateral Emitter Switched Thyristor

    NASA Astrophysics Data System (ADS)

    Choi, Young‑Hwan; Ji, In‑Hwan; Jeon, Byung‑Chul; Choi, Yearn‑Ik; Han, Min‑Koo

    2006-04-01

    A new circuit to protect lateral emitter switched thyristors (LESTs) for high voltage current saturation is proposed. We fabricated this circuit by employing a widely used process compatible with insulated gate bipolar transistors (IGBTs). When the floating n+ voltage is larger than the threshold voltage of protecting metal oxide semiconductor field effect transistor (MOSFET), the protective circuit alters the operation of the LEST from regenerative mode to non-regenerative mode. Experimental results showed that a high voltage current saturation exceeding 200 V was measured in the LEST with the proposed protective circuit, while the current saturation of the conventional LEST was limited to 17 V. This allowed the LEST to withstand the hard switching fault (HSF) condition over 10 μs during the hard switching fault (HSF) condition.

  3. Improvement of the pad wear shape in fixed abrasive chemical-mechanical polishing for manufacturing optical components

    NASA Astrophysics Data System (ADS)

    Nguyen, N. Y.; Tian, Y. B.; Zhong, Z. W.

    2015-07-01

    Fixed abrasive chemical mechanical polishing has some advantages in generating planarity surfaces of optical components. The surface after polishing has better uniformity, and the material removal rate is much more than the traditional chemical mechanical polishing. The pad wear shape has a significant effect on the uniformity of the surface in the chemical mechanical polishing process. The shape of the pad after wear is almost concave, and it has been challenging to create a flat surface. Therefore, there is a requirement for creating a better pad shape. The better the pad shape is, the more uniform the surface is. Kinematic analysis has been done to investigate the effect of the conditioning process on the pad shape. Some proposals are presented to create a better pad shape. In this paper, kinematic aspects of effects of the conditioner speed and the pad speed on the pad shape were investigated. In addition, a new model, including new designs of the conditioner and pad, is proposed. The conditioner in the new model is static instead of oscillation. The new model generates a better uniformity of the pad shape compared to the old model. The result was validated by an algorithm which was validated by the experiments reported in our previous paper.

  4. Treatments for the synchronisation of bovine recipients for fixed-time embryo transfer and improvement of pregnancy rates.

    PubMed

    Bó, Gabriel A; Peres, Lucas Coelho; Cutaia, Lucas E; Pincinato, Danilo; Baruselli, Pietro S; Mapletoft, R J

    2011-01-01

    Although embryo transfer technology has been used commercially in cattle for many years, the inefficiency of oestrus detection, especially in recipients, has limited the widespread application of this technology. The most useful alternative to increase the number of recipients utilised in an embryo transfer program is the use of protocols that allow for embryo transfer without the need for oestrus detection, usually called fixed-time embryo transfer (FTET). Most current FTET protocols are based on progestin-releasing devices combined with oestradiol or GnRH, which control and synchronise follicular wave dynamics and ovulation. Conception rates to a single FTET have been reported to be similar to those after detection of oestrus, but pregnancy rates are higher because these treatments have increased the proportion of recipients that receive an embryo. Recent changes to treatments for FTET, such as the administration of eCG, have resulted in increased pregnancy rates and provide opportunities to make these treatments easier to perform on farm.

  5. Improving Read Disturb Characteristics by Using Double Common Source Line and Dummy Switch Architecture in Multi Level Cell NAND Flash Memory with Low Power Consumption

    NASA Astrophysics Data System (ADS)

    Kang, Myounggon; Park, Ki-Tae; Song, Youngsun; Lim, Youngho; Suh, Kang-Deog; Shin, Hyungcheol

    2011-04-01

    Two new NAND structures using double common source line (CSL) and dummy switch and their read operation schemes as a solution for NAND flash memories have been proposed. Compared with conventional scheme, the proposed read schemes improves read disturb characteristics beyond sub-30 nm technology node. By using proposed read scheme, the number of fail bits of proposed NAND was decreased than those of conventional NAND at read cycles. Also, it was proven that they contribute to improve the performance and suppress the power consumption. The proposed NAND was verified by both simulation and experimental measurements in a fabricated 40 nm multi level cell (MLC) NAND device.

  6. Cost-Benefit of Improving the Efficiency of Room Air Conditioners (Inverter and Fixed Speed) in India

    SciTech Connect

    Shah, Nihar; Abhyankar, Nikit; Park, Won Young; Phadke, Amol; Diddi, Saurabh; Ahuja, Deepanshu; Mukherjee, P. K.; Walia, Archana

    2016-06-30

    Improving efficiency of air conditioners (ACs) typically involves improving the efficiency of various components such as compressors, heat exchangers, expansion valves, refrigerant and fans. We estimate the incremental cost of improving the efficiency of room ACs based on the cost of improving the efficiency of its key components. Further, we estimate the retail price increase required to cover the cost of efficiency improvement, compare it with electricity bill savings, and calculate the payback period for consumers to recover the additional price of a more efficient AC. We assess several efficiency levels, two of which are summarized below in the report. The finding that significant efficiency improvement is cost effective from a consumer perspective is robust over a wide range of assumptions. If we assume a 50% higher incremental price compared to our baseline estimate, the payback period for the efficiency level of 3.5 ISEER is 1.1 years. Given the findings of this study, establishing more stringent minimum efficiency performance criteria (one star level) should be evaluated rigorously considering significant benefits to consumers, energy security and environment.

  7. Cost-Benefit of Improving the Efficiency of Room Air Conditioners (Inverter and Fixed Speed) in India

    SciTech Connect

    Phadke, Amol; Shah, Nihar; Abhyankar, Nikit; Park, Won Young; Diddi, Saurabh; Ahuja, Deepanshu; Mukherjee, P. K.; Walia, Archana

    2016-06-01

    Improving efficiency of air conditioners (ACs) typically involves improving the efficiency of various components such as compressors, heat exchangers, expansion valves, refrigerant,and fans. We estimate the incremental cost of improving the efficiency of room ACs based on the cost of improving the efficiency of its key components. Further, we estimate the retail price increase required to cover the cost of efficiency improvement, compare it with electricity bill savings, and calculate the payback period for consumers to recover the additional price of a more efficient AC. The finding that significant efficiency improvement is cost effective from a consumer perspective is robust over a wide range of assumptions. If we assume a 50% higher incremental price compared to our baseline estimate, the payback period for the efficiency level of 3.5 ISEER is 1.1 years. Given the findings of this study, establishing more stringent minimum efficiency performance criteria (one-star level) should be evaluated rigorously considering significant benefits to consumers, energy security, and environment

  8. Does tablet formulation alone improve adherence and persistence: a comparison of ezetimibe fixed dose combination versus ezetimibe separate pill combination?

    PubMed

    Bartlett, Louise E; Pratt, Nicole; Roughead, Elizabeth E

    2017-01-01

    The aim of this study was to compare adherence and persistence in patients who add ezetimibe to statin therapy as a separate pill combination (SPC) or fixed dose combination (FDC). This is a retrospective cohort study of prescription data conducted in an Australian health dataset. Two cohorts were identified: those dispensed statins and subsequently ezetimibe as either SPC or FDC. We compared adherence to combination therapy using the medication possession ratio (MPR), multivariate linear and logistic regression. Persistence to initial combination medicines and any lipid-lowering therapies were analysed using Kaplan Meyer survival and Cox proportional hazards models. A total of 3651 people initiated ezetimibe SPC and 5740 ezetimibe FDC. There was no significant difference in adherence with mean MPRs: ezetimibe SPC = 0.99 (95% confidence interval 0.98-1.01) and FDC = 0.97 (95% CI 0.95-0.99). One year persistence rates to initial combination medicines were ezetimibe SPC 49.1% vs. FDC 62.4%; hazard ratio (HR) = 1.81 (95% CI 1.76-1.90). However, persistence to any lipid-lowering therapy was higher in those initiating ezetimibe SPC = 84.9% vs. FDC = 76%; HR = 0.62 (95% CI 0.55-0.72). One year persistence rates to any two lipid-lowering medicines were similar: ezetimibe SPC 65.2% and FDC 65%. In this study FDCs have little impact on either adherence or persistence to combination lipid-lowering therapy in people who have been taking statins. The benefit of higher persistence to FDCs in first episode of treatment with initial medicines is debatable as persistence to dual therapy was similar in both cohorts. © 2016 The British Pharmacological Society.

  9. Coaxial Switch

    DTIC Science & Technology

    2014-04-23

    08-2015 Publication Coaxial Switch David J. Bamford et al Naval Undersea Warfare Center Division, Newport 1176 Howell Street, Bldg 102T, Code 00L...Distribution A A coaxial switch having a housing and a shaft extending through and rotatably mounted to the housing. The shaft extends from opposite...conductor members are electrically connected together. When the coaxial switch is engaged, the conductor members are inserted into the connector body

  10. SPARK GAP SWITCH

    DOEpatents

    Neal, R.B.

    1957-12-17

    An improved triggered spark gap switch is described, capable of precisely controllable firing time while switching very large amounts of power. The invention in general comprises three electrodes adjustably spaced and adapted to have a large potential impressed between the outer electrodes. The central electrode includes two separate elements electrically connected togetaer and spaced apart to define a pair of spark gaps between the end electrodes. Means are provided to cause the gas flow in the switch to pass towards the central electrode, through a passage in each separate element, and out an exit disposed between the two separate central electrode elements in order to withdraw ions from the spark gap.

  11. High Power Switching Transistor

    NASA Technical Reports Server (NTRS)

    Hower, P. L.; Kao, Y. C.; Carnahan, D. C.

    1983-01-01

    Improved switching transistors handle 400-A peak currents and up to 1,200 V. Using large diameter silicon wafers with twice effective area as D60T, form basis for D7 family of power switching transistors. Package includes npn wafer, emitter preform, and base-contact insert. Applications are: 25to 50-kilowatt high-frequency dc/dc inverters, VSCF converters, and motor controllers for electrical vehicles.

  12. Optical switches and switching methods

    DOEpatents

    Doty, Michael

    2008-03-04

    A device and method for collecting subject responses, particularly during magnetic imaging experiments and testing using a method such as functional MRI. The device comprises a non-metallic input device which is coupled via fiber optic cables to a computer or other data collection device. One or more optical switches transmit the subject's responses. The input device keeps the subject's fingers comfortably aligned with the switches by partially immobilizing the forearm, wrist, and/or hand of the subject. Also a robust nonmetallic switch, particularly for use with the input device and methods for optical switching.

  13. Improving short-term forecasting during ramp events by means of Regime-Switching Artificial Neural Networks

    NASA Astrophysics Data System (ADS)

    Gallego, C.; Costa, A.; Cuerva, A.

    2010-09-01

    Since nowadays wind energy can't be neither scheduled nor large-scale storaged, wind power forecasting has been useful to minimize the impact of wind fluctuations. In particular, short-term forecasting (characterised by prediction horizons from minutes to a few days) is currently required by energy producers (in a daily electricity market context) and the TSO's (in order to keep the stability/balance of an electrical system). Within the short-term background, time-series based models (i.e., statistical models) have shown a better performance than NWP models for horizons up to few hours. These models try to learn and replicate the dynamic shown by the time series of a certain variable. When considering the power output of wind farms, ramp events are usually observed, being characterized by a large positive gradient in the time series (ramp-up) or negative (ramp-down) during relatively short time periods (few hours). Ramp events may be motivated by many different causes, involving generally several spatial scales, since the large scale (fronts, low pressure systems) up to the local scale (wind turbine shut-down due to high wind speed, yaw misalignment due to fast changes of wind direction). Hence, the output power may show unexpected dynamics during ramp events depending on the underlying processes; consequently, traditional statistical models considering only one dynamic for the hole power time series may be inappropriate. This work proposes a Regime Switching (RS) model based on Artificial Neural Nets (ANN). The RS-ANN model gathers as many ANN's as different dynamics considered (called regimes); a certain ANN is selected so as to predict the output power, depending on the current regime. The current regime is on-line updated based on a gradient criteria, regarding the past two values of the output power. 3 Regimes are established, concerning ramp events: ramp-up, ramp-down and no-ramp regime. In order to assess the skillness of the proposed RS-ANN model, a single

  14. Platform switching and bone platform switching.

    PubMed

    Carinci, Francesco; Brunelli, Giorgio; Danza, Matteo

    2009-01-01

    Bone platform switching involves an inward bone ring in the coronal part of the implant that is in continuity with the alveolar bone crest. Bone platform switching is obtained by using a dental fixture with a reverse conical neck. A retrospective study was performed to evaluate the effectiveness of conventional vs reverse conical neck implants. In the period between May 2004 and November 2007, 86 patients (55 females and 31 males; median age, 53 years) were operated and 234 implants were inserted: 40 and 194 were conventional vs reverse conical neck implants, respectively. Kaplan-Meier algorithm and Cox regression were used to detect those variables associated with the clinical outcome. No differences in survival and success rates were detected between conventional vs reverse conical neck implants alone or in combination with any of the studied variables. Although bone platform switching leads to several advantages, no statistical difference in alveolar crest resorption is detected in comparison with reverse conical neck implants. We suppose that the proximity of the implant abutment junction to the alveolar crestal bone gives no protection against the microflora contained in the micrograph. Additional studies on larger series and a combination of platform switching and bone platform switching could lead to improved clinical outcomes.

  15. Improvement of dumping syndrome and oversecretion of glucose-dependent insulinotropic polypeptide following a switch from olanzapine to quetiapine in a patient with schizophrenia.

    PubMed

    Watanabe, Aiko; Fukui, Naoki; Suzuki, Yutaro; Motegi, Takaharu; Igeta, Hirofumi; Tsuneyama, Nobuto; Someya, Toshiyuki

    2015-01-01

    Among the most important adverse effects of antipsychotics is abnormal glucose metabolism, which includes not only hyperglycemia but hyperinsulinemia and hypoglycemia. We have previously described five patients who experienced hypoglycemia during treatment with antipsychotics. Thus, an anamnesis of gastric surgery, which often causes dumping syndrome, and treatment with antipsychotics may synergistically induce hypoglycemia. We describe here a patient with schizophrenia under treatment of olanzapine and an anamnesis of gastric surgery, who experienced late dumping syndrome, hyperinsulinemia and overactivation of glucose-dependent insulinotropic polypeptide. Dumping syndrome, however, was improved after the patient was switched from olanzapine to quetiapine.

  16. The VA augmentation and switching treatments for improving depression outcomes (VAST-D) study: Rationale and design considerations.

    PubMed

    Mohamed, Somaia; Johnson, Gary R; Vertrees, Julia E; Guarino, Peter D; Weingart, Kimberly; Young, Ilanit Tal; Yoon, Jean; Gleason, Theresa C; Kirkwood, Katherine A; Kilbourne, Amy M; Gerrity, Martha; Marder, Stephen; Biswas, Kousick; Hicks, Paul; Davis, Lori L; Chen, Peijun; Kelada, AlexandraMary; Huang, Grant D; Lawrence, David D; LeGwin, Mary; Zisook, Sidney

    2015-10-30

    Because two-thirds of patients with Major Depressive Disorder do not achieve remission with their first antidepressant, we designed a trial of three "next-step" strategies: switching to another antidepressant (bupropion-SR) or augmenting the current antidepressant with either another antidepressant (bupropion-SR) or with an atypical antipsychotic (aripiprazole). The study will compare 12-week remission rates and, among those who have at least a partial response, relapse rates for up to 6 months of additional treatment. We review seven key efficacy/effectiveness design decisions in this mixed "efficacy-effectiveness" trial.

  17. ION SWITCH

    DOEpatents

    Cook, B.

    1959-02-10

    An ion switch capable of transferring large magnitudes of power is described. An ion switch constructed in accordance with the invention includes a pair of spaced control electrodes disposed in a highly evacuated region for connection in a conventional circuit to control the passing of power therethrough. A controllable ionic conduction path is provided directiy between the control electrodes by a source unit to close the ion switch. Conventional power supply means are provided to trigger the source unit and control the magnitude, durations and pulse repetition rate of the aforementioned ionic conduction path.

  18. A critical error that needs to be fixed to improve climate model simulations and projections around the globe

    NASA Astrophysics Data System (ADS)

    Sardeshmukh, P. D.; Compo, G. P.; Penland, C.; McColl, C.

    2013-12-01

    A number of recent studies (e.g. Shin and Sardeshmukh, Climate Dynamics 2011) have established that accurate representation of regional climate changes around the globe requires accurate representation of both the magnitude and pattern of tropical SST changes. Discrepancies of 20th century climate model simulations with respect to observations are attributable not only to unforced natural variability, i.e. climate noise, but also significantly to errors in representing the forced climate change signal in tropical SSTs. The models (both CMIP3 and CMIP5) are not only deficient in capturing the spatial patterns of observed tropical SST trends but also systematically underestimate their magnitude. This systematic model tendency to produce unrealistic spatially bland tropical SST responses to radiative forcing changes has ripple effects around the globe through atmospheric teleconnections. It leads to large errors (sometimes even of sign) in reproducing, for instance, observed long-term trends in the North Atlantic and North Pacific oscillations and changes in regional extreme weather statistics associated with those oscillations. A comprehensive intercomparison study of CMIP5 model simulations of the 1871 to 2010 period with observations, and also with large ensembles of AMIP simulations of the same period with prescribed observed SSTs, will be described to lend further support to these conclusions. Improving the representation of tropical SST changes is a good example of a 'cutting-edge challenge' in climate change science that needs to be addressed to generate confidence in 21st century climate changes around the globe. Some potentially promising avenues to address this challenge will also be discussed in the talk.

  19. Arterial switch.

    PubMed

    Planche, C; Lacour-Gayet, F; Serraf, A

    1998-01-01

    A relatively large spectra of anatomic variations are found within the unifying features of discordant ventriculoarterial connections. Variants that lend themselves to anatomic repair by the arterial switch operation are discussed, these include transposition of the great arteries with intact ventricular septum (TGA IVS), TGA associated with a ventricular septal defect (TGA VSD), double-outlet right ventricle with subpulmonary VSD (DORV VSD), and TGA or DORV with VSD associated with coarctation. Double discordance with VSD, which is currently treated by double switch or Rastelli and atrial switch and which probably represents, in our department, the only remaining indication for atrial switch, is not discussed. Also, we exclude TGA associated with pulmonary stenosis, which is treated by Rastelli or REV operation.

  20. Magnetic switching

    NASA Astrophysics Data System (ADS)

    Kirbie, H. C.

    1989-04-01

    Magnetic switching is a pulse compression technique that uses a saturable inductor (reactor) to pass pulses of energy between two capacitors. A high degree of pulse compression can be achieved in a network when several of these simple, magnetically switched circuits are connected in series. Individual inductors are designed to saturate in cascade as a pulse moves along the network. The technique is particularly useful when a single-pulse network must be very reliable or when a multi-pulse network must operate at a high pulse repetition frequency (PRF). Today, magnetic switches trigger spark gaps, sharpen the risetimes of high energy pulses, power large lasers, and drive high PRF linear induction accelerators. This paper will describe the technique of magnetic pulse compression using simple networks and design equations. A brief review of modern magnetic materials and of their role in magnetic switch design will be presented.

  1. Improved method for extraction and detection of Helicobacter pylori DNA in formalin-fixed paraffin embedded gastric biopsies using laser micro-dissection

    PubMed Central

    Loayza, María Fernanda; Villavicencio, Fernando Xavier; Santander, Stephanie Carolina; Baldeón, Manuel; Ponce, Lourdes Karina; Salvador, Iván; Vivar Díaz, Nicolás

    2014-01-01

    To assess the molecular events exerted by Helicobacter pylori interacting directly with gastric epithelial cells, an improved procedure for microbial DNA isolation from stained hematoxilin-eosin gastric biopsies was developed based on laser micro-dissection (LM) [1]. Few articles have described the use of LM to select and detect H. pylori genome from formalin-fixed paraffin embedded gastric tissue [2]. To improve the yield and quality of DNA isolated from H. pylori contacting intestinal epithelial cells, the following conditions were established after modification of the QIAamp DNA Micro kit. • Use of at least 25 cut sections of 10–20 μm of diameter and 3 μm thick with more than 10 bacteria in each cut. • Lysis with 30 μL of tissue lysis buffer and 20 μL of proteinase K (PK) with the tube in an upside-down position. • The use of thin purification columns with 35 μL of elution buffer. The mean of DNA concentration obtained from 25 LM cut sections was 1.94± 0 .16 ng/μL, and it was efficiently amplified with qPCR in a Bio Rad iCycler instrument. The LM can improve the sample selection and DNA extraction for molecular analysis of H. pylori associated with human gastric epithelium. PMID:26150965

  2. Enhancing nitrogen removal efficiency and reducing nitrate liquor recirculation ratio by improving simultaneous nitrification and denitrification in integrated fixed-film activated sludge (IFAS) process.

    PubMed

    Bai, Yang; Zhang, Yaobin; Quan, Xie; Chen, Shuo

    2016-01-01

    An integrated fixed-film activated sludge (IFAS) process (G1) and an activated sludge anoxic-oxic process (G2) were operated at nitrate liquor recirculation ratio (R) of 100, 200 and 300% to investigate the feasibility of enhancing nitrogen removal efficiency (RTN) and reducing R by improving simultaneous nitrification and denitrification (SND) in the IFAS process. The results showed that the effluent NH4(+)-N and total nitrogen (TN) of G1 at R of 200% were less than 1.5 and 14.5 mg/L, satisfying the Chinese discharge standard (NH4(+)-N < 5 mg/L; TN < 15 mg/L). However, the effluent NH4(+)-N and TN of G2 at R of 300% were higher than 8.5 and 15.3 mg/L. It indicated that better RTN could be achieved at a lower R in the IFAS process. The polymerase chain reaction-denaturing gradient gel electrophoresis results implied that nitrifiers and denitrifiers co-existed in one microbial community, facilitating the occurrence of SND in the aerobic reactor of G1, and the contribution of SND to TN removal efficiency ranged 15-19%, which was the main reason that the RTN was improved in the IFAS process. Therefore, the IFAS process was an effective method for improving RTN and reducing R. In practical application, this advantage of the IFAS process can decrease the electricity consumption for nitrate liquor recirculation flow, thereby saving operational costs.

  3. Nucleosome Switches

    NASA Astrophysics Data System (ADS)

    Schwab, David J.; Bruinsma, Robijn F.; Rudnick, Joseph; Widom, Jonathan

    2008-06-01

    We present a statistical-mechanical model for the positioning of nucleosomes along genomic DNA molecules as a function of the strength of the binding potential and the chemical potential of the nucleosomes. We show that a significant section of the DNA is composed of two-level nucleosome switching regions where the nucleosome distribution undergoes a localized, first-order transition. The location of the nucleosome switches shows a strong correlation with the location of gene-regulation regions.

  4. Nucleosome switches.

    PubMed

    Schwab, David J; Bruinsma, Robijn F; Rudnick, Joseph; Widom, Jonathan

    2008-06-06

    We present a statistical-mechanical model for the positioning of nucleosomes along genomic DNA molecules as a function of the strength of the binding potential and the chemical potential of the nucleosomes. We show that a significant section of the DNA is composed of two-level nucleosome switching regions where the nucleosome distribution undergoes a localized, first-order transition. The location of the nucleosome switches shows a strong correlation with the location of gene-regulation regions.

  5. Effect of social media in improving knowledge among patients having fixed appliance orthodontic treatment: A single-center randomized controlled trial.

    PubMed

    Al-Silwadi, Fadi M; Gill, Daljit S; Petrie, Aviva; Cunningham, Susan J

    2015-08-01

    Research has shown that orthodontic patients are more likely to retain information presented in an audiovisual format. However, there has been little research on the effectiveness of audiovisual information provided through different routes such as the Internet. This parallel-group randomized controlled trial assessed whether provision of audiovisual information on the YouTube (Google, San Bruno, Calif) Web site to orthodontic patients undergoing fixed appliance treatment results in improved patient knowledge when compared with conventional methods of information provision. The effects of sex and ethnicity were also investigated. Participants were recruited from the Department of Orthodontics of the Eastman Dental Hospital, University College London Hospitals NHS Foundation Trust, United Kingdom. The patients were 13 years of age and over, with no history of orthodontic treatment, and patient and parental (where appropriate) consent were obtained. The participants were randomized into control (n = 34) and intervention (n = 33) groups using a random number table; there was stratification based on age group, with permuted blocks of 10 patients. Both groups were given routine verbal and written patient information related to fixed appliances, and the participants in the intervention group were sent 3 e-mails over 6 weeks requesting that they view a 6-minute YouTube video containing similar information but in audiovisual format. Patient knowledge was measured using identical questionnaires answered on the day of recruitment (baseline) and again 6 to 8 weeks later. The researchers were unaware of group allocations when enrolling patients and scoring questionnaires. Sixty participants (89.55%) completed the study. Those who completed the trial in the intervention group (n = 30) demonstrated significantly greater improvements in knowledge than did those in the control group (n = 30), scoring, on average, almost 1 point more (95% CI for the difference, 0.305-1.602; P = 0

  6. Configurable hot spot fixing system

    NASA Astrophysics Data System (ADS)

    Kajiwara, Masanari; Kobayashi, Sachiko; Mashita, Hiromitsu; Aburada, Ryota; Furuta, Nozomu; Kotani, Toshiya

    2014-03-01

    Hot spot fixing (HSF) method has been used to fix many hot spots automatically. However, conventional HSF based on a biasing based modification is difficult to fix many hot spots under a low-k1 lithography condition. In this paper we proposed a new HSF, called configurable hotspot fixing system. The HSF has two major concepts. One is a new function to utilize vacant space around a hot spot by adding new patterns or extending line end edges around the hot spot. The other is to evaluate many candidates at a time generated by the new functions. We confirmed the proposed HSF improves 73% on the number of fixing hot spots and reduces total fixing time by 50% on a device layout equivalent to 28nm-node. The result shows the proposed HSF is effective for layouts under the low-k1 lithography condition.

  7. Thermionic gas switch

    DOEpatents

    Hatch, G.L.; Brummond, W.A.; Barrus, D.M.

    1984-04-05

    The present invention is directed to an improved temperature responsive thermionic gas switch utilizing a hollow cathode and a folded emitter surface area. The folded emitter surface area of the thermionic switch substantially increases the on/off ratio by changing the conduction surface area involved in the two modes thereof. The improved switch of this invention provides an on/off ratio of 450:1 compared to the 10:1 ratio of the prior known thermionic switch, while providing for adjusting the on current. In the improved switch of this invention the conduction area is made small in the off mode, while in the on mode the conduction area is made large. This is achieved by utilizing a folded hollow cathode configuration and utilizing a folded emitter surface area, and by making the dimensions of the folds small enough so that a space charge will develop in the convolutions of the folds and suppress unignited current, thus limiting the current carrying surface in the off mode.

  8. Evidence towards Improved Estimation of Respiratory Muscle Effort from Diaphragm Mechanomyographic Signals with Cardiac Vibration Interference Using Sample Entropy with Fixed Tolerance Values

    PubMed Central

    Sarlabous, Leonardo; Torres, Abel; Fiz, José A.; Jané, Raimon

    2014-01-01

    The analysis of amplitude parameters of the diaphragm mechanomyographic (MMGdi) signal is a non-invasive technique to assess respiratory muscle effort and to detect and quantify the severity of respiratory muscle weakness. The amplitude of the MMGdi signal is usually evaluated using the average rectified value or the root mean square of the signal. However, these estimations are greatly affected by the presence of cardiac vibration or mechanocardiographic (MCG) noise. In this study, we present a method for improving the estimation of the respiratory muscle effort from MMGdi signals that is robust to the presence of MCG. This method is based on the calculation of the sample entropy using fixed tolerance values (fSampEn), that is, with tolerance values that are not normalized by the local standard deviation of the window analyzed. The behavior of the fSampEn parameter was tested in synthesized mechanomyographic signals, with different ratios between the amplitude of the MCG and clean mechanomyographic components. As an example of application of this technique, the use of fSampEn was explored also in recorded MMGdi signals, with different inspiratory loads. The results with both synthetic and recorded signals indicate that the entropy parameter is less affected by the MCG noise, especially at low signal-to-noise ratios. Therefore, we believe that the proposed fSampEn parameter could improve estimates of respiratory muscle effort from MMGdi signals with the presence of MCG interference. PMID:24586436

  9. Evidence towards improved estimation of respiratory muscle effort from diaphragm mechanomyographic signals with cardiac vibration interference using sample entropy with fixed tolerance values.

    PubMed

    Sarlabous, Leonardo; Torres, Abel; Fiz, José A; Jané, Raimon

    2014-01-01

    The analysis of amplitude parameters of the diaphragm mechanomyographic (MMGdi) signal is a non-invasive technique to assess respiratory muscle effort and to detect and quantify the severity of respiratory muscle weakness. The amplitude of the MMGdi signal is usually evaluated using the average rectified value or the root mean square of the signal. However, these estimations are greatly affected by the presence of cardiac vibration or mechanocardiographic (MCG) noise. In this study, we present a method for improving the estimation of the respiratory muscle effort from MMGdi signals that is robust to the presence of MCG. This method is based on the calculation of the sample entropy using fixed tolerance values (fSampEn), that is, with tolerance values that are not normalized by the local standard deviation of the window analyzed. The behavior of the fSampEn parameter was tested in synthesized mechanomyographic signals, with different ratios between the amplitude of the MCG and clean mechanomyographic components. As an example of application of this technique, the use of fSampEn was explored also in recorded MMGdi signals, with different inspiratory loads. The results with both synthetic and recorded signals indicate that the entropy parameter is less affected by the MCG noise, especially at low signal-to-noise ratios. Therefore, we believe that the proposed fSampEn parameter could improve estimates of respiratory muscle effort from MMGdi signals with the presence of MCG interference.

  10. Improved RNA quality and TaqMan® Pre-amplification method (PreAmp) to enhance expression analysis from formalin fixed paraffin embedded (FFPE) materials

    PubMed Central

    Li, Jinghuan; Smyth, Paul; Cahill, Susanne; Denning, Karen; Flavin, Richard; Aherne, Sinead; Pirotta, Marco; Guenther, Simone M; O'Leary, John J; Sheils, Orla

    2008-01-01

    Background Archival formalin-fixed paraffin-embedded (FFPE) tissues represent an abundant source of clinical specimens; however their use is limited in applications involving analysis of gene expression due to RNA degradation and modification during fixation and processing. This study improved the quality of RNA extracted from FFPE by introducing a heating step into the selected extraction protocols. Further, it evaluated a novel pre-amplification system (PreAmp) designed to enhance expression analysis from tissue samples using assays with a range of amplicon size (62–164 bp). Results Results from the Bioanalyzer and TaqMan® data showed improvement of RNA quality extracted using the modified protocols from FFPE. Incubation at 70°C for 20 minutes was determined to be the best condition of those tested to disrupt cross-links while not compromising RNA integrity. TaqMan® detection was influenced by master mix, amplicon size and the incorporation of a pre-amplification step. TaqMan® PreAmp consistently achieved decreased CT values in both snap frozen and FFPE aliquots compared with no pre-amplification. Conclusion Modification to extraction protocols has facilitated procurement of RNA that may be successfully amplified using QRT-PCR. TaqMan® PreAmp system is a robust and practical solution to limited quantities of RNA from FFPE extracts. PMID:18254955

  11. A Review of NEPA, a Novel Fixed Antiemetic Combination with the Potential for Enhancing Guideline Adherence and Improving Control of Chemotherapy-Induced Nausea and Vomiting.

    PubMed

    Hesketh, Paul J; Aapro, Matti; Jordan, Karin; Schwartzberg, Lee; Bosnjak, Snezana; Rugo, Hope

    2015-01-01

    Combination antiemetic regimens targeting multiple molecular pathways associated with emesis have become the standard of care for prevention of chemotherapy-induced nausea and vomiting (CINV) related to highly and moderately emetogenic chemotherapies. Antiemetic consensus guidelines from several professional societies are widely available and updated regularly as new data emerges. Unfortunately, despite substantial research supporting the notion that guideline conformity improves CINV control, adherence to antiemetic guidelines is unsatisfactory. While studies are needed to identify specific barriers to guideline use and explore measures to enhance adherence, a novel approach has been taken to improve clinician adherence and patient compliance, with the development of a new combination antiemetic. NEPA is an oral fixed combination of a new highly selective NK1 receptor antagonist (RA), netupitant, and the pharmacologically and clinically distinct 5-HT3 RA, palonosetron. This convenient antiemetic combination offers guideline-consistent prophylaxis by targeting two critical pathways associated with CINV in a single oral dose administered only once per cycle. This paper will review and discuss the NEPA data in the context of how this first combination antiemetic may overcome some of the barriers interfering with adherence to antiemetic guidelines, enhance patient compliance, and offer a possible advance in the prevention of CINV for patients.

  12. A Review of NEPA, a Novel Fixed Antiemetic Combination with the Potential for Enhancing Guideline Adherence and Improving Control of Chemotherapy-Induced Nausea and Vomiting

    PubMed Central

    Schwartzberg, Lee; Rugo, Hope

    2015-01-01

    Combination antiemetic regimens targeting multiple molecular pathways associated with emesis have become the standard of care for prevention of chemotherapy-induced nausea and vomiting (CINV) related to highly and moderately emetogenic chemotherapies. Antiemetic consensus guidelines from several professional societies are widely available and updated regularly as new data emerges. Unfortunately, despite substantial research supporting the notion that guideline conformity improves CINV control, adherence to antiemetic guidelines is unsatisfactory. While studies are needed to identify specific barriers to guideline use and explore measures to enhance adherence, a novel approach has been taken to improve clinician adherence and patient compliance, with the development of a new combination antiemetic. NEPA is an oral fixed combination of a new highly selective NK1 receptor antagonist (RA), netupitant, and the pharmacologically and clinically distinct 5-HT3 RA, palonosetron. This convenient antiemetic combination offers guideline-consistent prophylaxis by targeting two critical pathways associated with CINV in a single oral dose administered only once per cycle. This paper will review and discuss the NEPA data in the context of how this first combination antiemetic may overcome some of the barriers interfering with adherence to antiemetic guidelines, enhance patient compliance, and offer a possible advance in the prevention of CINV for patients. PMID:26421300

  13. Magnetic switch coupling to synchronize magnetic modulators

    DOEpatents

    Reed, Kim W.; Kiekel, Paul

    1999-01-01

    Apparatus for synchronizing the output pulses from a pair of magnetic switches. An electrically conductive loop is provided between the pair of switches with the loop having windlings about the core of each of the magnetic switches. The magnetic coupling created by the loop removes voltage and timing variations between the outputs of the two magnetic switches caused by any of a variety of factors. The only remaining variation is a very small fixed timing offset caused by the geometry and length of the loop itself.

  14. Magnetic switch coupling to synchronize magnetic modulators

    DOEpatents

    Reed, K.W.; Kiekel, P.

    1999-04-27

    Apparatus for synchronizing the output pulses from a pair of magnetic switches is disclosed. An electrically conductive loop is provided between the pair of switches with the loop having windings about the core of each of the magnetic switches. The magnetic coupling created by the loop removes voltage and timing variations between the outputs of the two magnetic switches caused by any of a variety of factors. The only remaining variation is a very small fixed timing offset caused by the geometry and length of the loop itself. 13 figs.

  15. Comparative effectiveness of switching antipsychotic drug treatment to aripiprazole or ziprasidone for improving metabolic profile and atherogenic dyslipidemia: a 12-month, prospective, open-label study.

    PubMed

    Chen, Yuejin; Bobo, William V; Watts, Kara; Jayathilake, Karuna; Tang, Tinlai; Meltzer, Herbert Y

    2012-09-01

    We studied the effects of switching antipsychotic drug-treated patients with schizophrenia or bipolar disorder who evidenced adverse metabolic side effects as indicated by a triglyceride/high-density lipoprotein ratio (TG/HDL) ≥ 3.5 to aripiprazole (ARIP; 5-30 mg/day, n = 24) or ziprasidone (ZIP; 40-160 mg/day, n = 28). Anthropometric and metabolic measures, psychopathology, quality of life and motor adverse effects were assessed over a 52-week period with evaluations at baseline, 6, 12, 26 and 52 weeks. There were statistically significant improvements in body weight, body mass index (BMI), TG, HDL and TG/HDL which did not differ between treatments. However, numerous secondary measures including weight and BMI, and the proportion of patients who lost ≥ 7% or who no longer met criteria for obesity, favored ZIP over ARIP. Decreases in total cholesterol and increases in HDL-cholesterol also favored ZIP. On the other hand, decreases in TG/HDL ratio and reduction in HgbA1c favored ARIP. There were no significant time or group × time interaction effects for most psychopathology measures; however, Global Assessment of Functioning Scores favored ARIP at 6 and 12 months. We conclude that switching patients with evidence of metabolic side effects to either ARIP or ZIP may be beneficial for some, but not all metabolic measures, with minimal risk of worsening of psychopathology and possibly some benefit in that regard as well.

  16. Terminator Operon Reporter: combining a transcription termination switch with reporter technology for improved gene synthesis and synthetic biology applications

    PubMed Central

    Zampini, Massimiliano; Mur, Luis A. J.; Rees Stevens, Pauline; Pachebat, Justin A.; Newbold, C. James; Hayes, Finbarr; Kingston-Smith, Alison

    2016-01-01

    Synthetic biology is characterized by the development of novel and powerful DNA fabrication methods and by the application of engineering principles to biology. The current study describes Terminator Operon Reporter (TOR), a new gene assembly technology based on the conditional activation of a reporter gene in response to sequence errors occurring at the assembly stage of the synthetic element. These errors are monitored by a transcription terminator that is placed between the synthetic gene and reporter gene. Switching of this terminator between active and inactive states dictates the transcription status of the downstream reporter gene to provide a rapid and facile readout of the accuracy of synthetic assembly. Designed specifically and uniquely for the synthesis of protein coding genes in bacteria, TOR allows the rapid and cost-effective fabrication of synthetic constructs by employing oligonucleotides at the most basic purification level (desalted) and without the need for costly and time-consuming post-synthesis correction methods. Thus, TOR streamlines gene assembly approaches, which are central to the future development of synthetic biology. PMID:27220405

  17. Parallelization and Improvements of the Generalized Born Model with a Simple sWitching Function for Modern Graphics Processors

    PubMed Central

    Arthur, Evan J.; Brooks, Charles L.

    2016-01-01

    Two fundamental challenges of simulating biologically relevant systems are the rapid calculation of the energy of solvation, and the trajectory length of a given simulation. The Generalized Born model with a Simple sWitching function (GBSW) addresses these issues by using an efficient approximation of Poisson–Boltzmann (PB) theory to calculate each solute atom's free energy of solvation, the gradient of this potential, and the subsequent forces of solvation without the need for explicit solvent molecules. This study presents a parallel refactoring of the original GBSW algorithm and its implementation on newly available, low cost graphics chips with thousands of processing cores. Depending on the system size and nonbonded force cutoffs, the new GBSW algorithm offers speed increases of between one and two orders of magnitude over previous implementations while maintaining similar levels of accuracy. We find that much of the algorithm scales linearly with an increase of system size, which makes this water model cost effective for solvating large systems. Additionally, we utilize our GPU-accelerated GBSW model to fold the model system chignolin, and in doing so we demonstrate that these speed enhancements now make accessible folding studies of peptides and potentially small proteins. PMID:26786647

  18. Hamiltonian Switch Metropolis Monte Carlo Simulations for Improved Conformational Sampling of Intrinsically Disordered Regions Tethered to Ordered Domains of Proteins.

    PubMed

    Mittal, Anuradha; Lyle, Nicholas; Harmon, Tyler S; Pappu, Rohit V

    2014-08-12

    There is growing interest in the topic of intrinsically disordered proteins (IDPs). Atomistic Metropolis Monte Carlo (MMC) simulations based on novel implicit solvation models have yielded useful insights regarding sequence-ensemble relationships for IDPs modeled as autonomous units. However, a majority of naturally occurring IDPs are tethered to ordered domains. Tethering introduces additional energy scales and this creates the challenge of broken ergodicity for standard MMC sampling or molecular dynamics that cannot be readily alleviated by using generalized tempering methods. We have designed, deployed, and tested our adaptation of the Nested Markov Chain Monte Carlo sampling algorithm. We refer to our adaptation as Hamiltonian Switch Metropolis Monte Carlo (HS-MMC) sampling. In this method, transitions out of energetic traps are enabled by the introduction of an auxiliary Markov chain that draws conformations for the disordered region from a Boltzmann distribution that is governed by an alternative potential function that only includes short-range steric repulsions and conformational restraints on the ordered domain. We show using multiple, independent runs that the HS-MMC method yields conformational distributions that have similar and reproducible statistical properties, which is in direct contrast to standard MMC for equivalent amounts of sampling. The method is efficient and can be deployed for simulations of a range of biologically relevant disordered regions that are tethered to ordered domains.

  19. Optical switch

    DOEpatents

    Reedy, Robert P.

    1987-01-01

    An optical switching device (10) is provided whereby light from a first glass fiber (16) or a second glass fiber (14) may be selectively transmitted into a third glass fiber (18). Each glass fiber is provided with a focusing and collimating lens system (26, 28, 30). In one mode of operation, light from the first glass fiber (16) is reflected by a planar mirror (36) into the third glass fiber (18). In another mode of operation, light from the second glass fiber (14) passes directly into the third glass fiber (18). The planar mirror (36) is attached to a rotatable table (32) which is rotated to provide the optical switching.

  20. Optical switch

    DOEpatents

    Reedy, R.P.

    1987-11-10

    An optical switching device is provided whereby light from a first glass fiber or a second glass fiber may be selectively transmitted into a third glass fiber. Each glass fiber is provided with a focusing and collimating lens system. In one mode of operation, light from the first glass fiber is reflected by a planar mirror into the third glass fiber. In another mode of operation, light from the second glass fiber passes directly into the third glass fiber. The planar mirror is attached to a rotatable table which is rotated to provide the optical switching. 3 figs.

  1. Optical switch

    DOEpatents

    Reedy, R.P.

    1985-01-18

    An optical switching device is provided whereby light from a first glass fiber or a second glass fiber may be selectively transmitted into a third glass fiber. Each glass fiber is provided with a focusing and collimating lens system. In one mode of operation, light from the first glass fiber is reflected by a planar mirror into the third glass fiber. In another mode of operation, light from the second glass fiber passes directly into the third glass fiber. The planar mirror is attached to a rotatable table which is rotated to provide the optical switching.

  2. Low inductance gas switching.

    SciTech Connect

    Chavez, Ray; Harjes, Henry Charles III; Wallace, Zachariah; Elizondo, Juan E.

    2007-10-01

    The laser trigger switch (LTS) is a key component in ZR-type pulsed power systems. In ZR, the pulse rise time through the LTS is > 200 ns and additional stages of pulse compression are required to achieve the desired <100 ns rise time. The inductance of the LTS ({approx}500nH) in large part determines the energy transfer time through the switch and there is much to be gained in improving system performance and reducing system costs by reducing this inductance. The current path through the cascade section of the ZR LTS is at a diameter of {approx} 6-inches which is certainly not optimal from an inductance point of view. The LTS connects components of much greater diameter (typically 4-5 feet). In this LDRD the viability of switch concepts in which the diameter of cascade section is greatly increased have been investigated. The key technical question to be answered was, will the desired multi-channel behavior be maintained in a cascade section of larger diameter. This LDRD proceeded in 2 distinct phases. The original plan for the LDRD was to develop a promising switch concept and then design, build, and test a moderate scale switch which would demonstrate the key features of the concept. In phase I, a switch concept which meet all electrical design criteria and had a calculated inductance of 150 nH was developed. A 1.5 MV test switch was designed and fabrication was initiated. The LDRD was then redirected due to budgetary concerns. The fabrication of the switch was halted and the focus of the LDRD was shifted to small scale experiments designed to answer the key technical question concerning multi-channel behavior. In phase II, the Multi-channel switch test bed (MCST) was designed and constructed. The purpose of MCST was to provide a versatile, fast turn around facility for the study the multi-channel electrical breakdown behavior of a ZR type cascade switch gap in a parameter space near that of a ZR LTS. Parameter scans on source impedance, gap tilt, gap spacing and

  3. A simplification trial switching from nucleoside reverse transcriptase inhibitors to once-daily fixed-dose abacavir/lamivudine or tenofovir/emtricitabine in HIV-1-infected patients with virological suppression.

    PubMed

    Martínez, Esteban; Arranz, José A; Podzamczer, Daniel; Loncá, Montserrat; Sanz, José; Barragán, Patricia; Ribera, Esteban; Knobel, Hernando; Roca, Victor; Gutiérrez, Félix; Blanco, José L; Mallolas, Josep; Llibre, Josep M; Clotet, Bonaventura; Dalmau, David; Segura, Ferran; Arribas, José R; Cosín, Jaime; Barrufet, Pilar; Casas, Esperanza; Ferrer, Elena; Curran, Adrià; González, Alicia; Pich, Judit; Cruceta, Ana; Arnaiz, Joan A; Miró, José M; Gatell, José M

    2009-07-01

    Data comparing abacavir/lamivudine versus tenofovir/emtricitabine in antiretroviral-naive patients are controversial. We compared 48-week efficacy and safety of these combinations as substitutes of nucleosides in patients with virological suppression. We randomly assigned 333 HIV-1-infected patients on lamivudine-containing triple regimens with <200 copies per milliliter for at least 6 months to switch their nucleosides to either abacavir/lamivudine (n = 167) or tenofovir/emtricitabine (n = 166). The primary outcome was treatment failure ["switching = failure" intention to treat (ITT) analysis, noninferiority margin 12.5%]. Secondary outcomes were time to treatment failure, virological failure, adverse events, and changes in CD4 count, fasting plasma lipids, lipodystrophy, body fat, bone mineral density, and renal function. Treatment failure occurred in 32 patients (19%) on abacavir/lamivudine and 22 patients (13%) on tenofovir/emtricitabine [difference 5.9%; (95% confidence interval -2.1% to 14.0%), P = 0.06]. Four patients in the abacavir/lamivudine group versus none in the tenofovir/emtricitabine group developed virological failure [difference 2.4; (95% confidence interval 0.05 to 6.0), P = 0.04]. Twenty-three patients (14%) assigned to abacavir/lamivudine and 10 (6%) to tenofovir/lamivudine experienced grade 3 or 4 adverse effects (P = 0.03). CD4 counts and plasma lipids showed higher increments in the abacavir/lamivudine group than in the tenofovir/emtricitabine group. In HIV-1-infected patients with virological suppression, abacavir/lamivudine did not meet the noninferiority outcome for treatment efficacy compared with tenofovir/emtricitabine.

  4. Switching to aripiprazole in outpatients with schizophrenia experiencing insufficient efficacy and/or safety/tolerability issues with risperidone: a randomized, multicentre, open-label study.

    PubMed

    Ryckmans, V; Kahn, J P; Modell, S; Werner, C; McQuade, R D; Kerselaers, W; Lissens, J; Sanchez, R

    2009-05-01

    This study evaluated the safety/tolerability and effectiveness of aripiprazole titrated-dose versus fixed-dose switching strategies from risperidone in patients with schizophrenia experiencing insufficient efficacy and/or safety/tolerability issues. Patients were randomized to an aripiprazole titrated-dose (starting dose 5 mg/day) or fixed-dose (dose 15 mg/day) switching strategy with risperidone down-tapering. Primary endpoint was rate of discontinuation due to adverse events (AEs) during the 12-week study. Secondary endpoints included positive and negative syndrome scale (PANSS), clinical global impressions - improvement of illness scale (CGI-I), preference of medication (POM), subjective well-being under neuroleptics (SWN-K) and GEOPTE (Grupo Español para la Optimización del Tratamiento de la Esquizofrenia) scales. Rates of discontinuations due to AEs were similar between titrated-dose and fixed-dose strategies (3.5% vs. 5.0%; p=0.448). Improvements in mean PANSS total scores were similar between aripiprazole titrated-dose and fixed-dose strategies (-14.8 vs. -17.2; LOCF), as were mean CGI-I scores (2.9 vs. 2.8; p=0.425; LOCF) and SWN-K scores (+8.6 vs.+10.3; OC,+7.8 vs.+9.8; LOCF). Switching can be effectively and safely achieved through a titrated-dose or fixed-dose switching strategy for aripiprazole, with down-titration of risperidone.

  5. Switching Transistor

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Westinghouse Electric Corporation's D60T transistors are used primarily as switching devices for controlling high power in electrical circuits. It enables reduction in the number and size of circuit components and promotes more efficient use of energy. Wide range of application from a popcorn popper to a radio frequency generator for solar cell production.

  6. Fixed dose of long-acting erythropoietic stimulating agents at higher frequency improves appetite, reduces inflammation and corrects anaemia in patients on haemodialysis.

    PubMed

    Liu, Wen-Sheng; Chu, Da-Chen; Chan, Hsiang-Lin; Li, Szu-Yuan; Liu, Chih-Kuang; Yang, Chih-Yu; Chen, Yu-Wei; Lee, Pui-Ching; Lai, Yen-Ting; Lin, Chih-Ching

    2016-10-01

    Anaemia is an important issue in patients undergoing haemodialysis. We aimed to identify a better dosing schedule of a fixed monthly dose of continuous erythropoietin receptor activator (CERA) in patients with chronic kidney disease (CKD) on haemodialysis. The CERA dosing schedule included 100 μg once monthly for 2 months, 50 μg twice monthly for 2 months and then 100 μg once monthly for two months. The effectiveness was determined by comparing haematocrit, nutritional status (serum protein and albumin) and inflammatory markers (tumour necrosis factor (TNF)-α, interleukin (IL)-1, IL-6 and Hepcidin) at the beginning of the study with those at the end of the study. Forty-seven out of 67 patients completed the trial. At the end, haematocrit was significantly higher (34.51 vs 33.22%, P=.004), levels of inflammatory markers were significantly lower (TNF-α (30.71 vs 35.67 ng/mL, P=.007), IL-6 (5.12 vs 7.95 ng/mL, P=.033), hepcidin (60.39 vs 74.39 ng/mL, P=.002)), blood glucose levels were significantly lower (112.40 vs 139.02 mg/dL, P=.003) and albumin was significantly higher (4.11 vs 3.98, P=.001). Patients with a better than average response had a lower initial number of red blood cells (3.3 vs 3.6 × 10(6) /mm(3) , P=.025) and a lower IL-1 (3.8 vs 12.9 ng/mL, P=.01). They also had significantly lower blood glucose levels at the end. (91.3 vs 124.0 mg/dL, P=.03). We demonstrate that a fixed monthly dose of CERA at a twice monthly dosing schedule improves nutrition, reduces the inflammation and corrects anaemia in patients on haemodialysis. This finding may provide a new strategy for treating CKD-related anaemia. © 2016 John Wiley & Sons Australia, Ltd.

  7. Application of Fixed Scale Approach to Static Quark Free Energies in Quenched and 2+1 Flavor Lattice QCD with Improved Wilson Quark Action

    NASA Astrophysics Data System (ADS)

    Maezawa, Y.; Umeda, T.; Aoki, S.; Ejiri, S.; Hatsuda, T.; Kanaya, K.; Ohno, H.; WHOT-QCD Collaboration

    2012-11-01

    The free energies of static quarks and the Debye screening masses in the quark gluon plasma are studied using Polyakov-line correlation functions in lattice QCD adopting the fixed-scale approach in which temperature is varied without changing the spatial volume and the renormalization factors. We calculate static-quark free energies in various color channels in the high temperature phase up to about 3.5 times the (pseudo-)critical temperature, performing lattice simulations both in quenched and 2 + 1 flavor QCD. For the quenched simulations, we adopt the plaquette gauge action on anisotropic 20^3 × N_t lattices with N_t = 8-26 at the renormalized anisotropy a_s / a_t ≃ 4. For 2 + 1 flavor QCD, we adopt the renormalization-group improved Iwasaki gluon action and the non-perturbatively O(a)-improved Wilson quark action on isotropic 32^3 × N_t lattices with N_t = 4-12 at m_{PS}/m_{V} = 0.63 (0.74) for the light (strange) flavors. We find that the color-singlet free energies at high temperatures converge to the zero-temperature static-quark potential evaluated from the Wilson-loop at short distances. This is in accordance with the theoretical expectation that the short distance physics is insensitive to the temperature. At long distances, the free energies approach twice the single-quark free energies, implying that the interaction between static quarks is fully screened. We find that the static-quark free energies for various color channels turn out to be well described by the screened Coulomb form, and the color-channel dependence of the inter-quark interaction can be described by the kinetic Casimir factor inspired from the lowest order perturbation theory. We also discuss comparison with a prediction of the thermal perturbation theory and flavor dependence of the screening masses.

  8. Improvement of switching endurance of conducting-bridge random access memory by addition of metal-ion-containing ionic liquid

    NASA Astrophysics Data System (ADS)

    Kinoshita, Kentaro; Sakaguchi, Atsushi; Harada, Akinori; Yamaoka, Hiroki; Kishida, Satoru; Fukaya, Yukinobu; Nokami, Toshiki; Itoh, Toshiyuki

    2017-04-01

    A remarkable improvement of cycling endurance was achieved by the addition of a trace amount of an ionic liquid ([bmim][Tf2N]) containing Cu(Tf2N)2 to the HfO2 layer of a conducting-bridge random access memory (CBRAM) with a Cu/HfO2/Pt structure. The improvement was brought about by the significant improvement of the dispersion of a set voltage and the suppression of the generation and migration of oxygen vacancies owing to the smooth diffusion of Cu ions in ionic liquids.

  9. Switched power workshop. [Switched power electron guns

    SciTech Connect

    Palmer, R.B.

    1988-01-01

    This paper discusses the design of a switched power electron gun. Particular topics discussed are: vacuum photodiode switch; laser switched solid state diodes; gun performance; charging supply; and laser requirements. (LSP)

  10. Improved technique for fluorescence in situ hybridisation analysis of isolated nuclei from archival, B5 or formalin fixed, paraffin wax embedded tissue.

    PubMed

    Schurter, M J; LeBrun, D P; Harrison, K J

    2002-04-01

    Fluorescence in situ hybridisation (FISH) is an effective method to detect chromosomal alterations in a variety of tissue types, including archived paraffin wax embedded specimens fixed in B5 or formalin. However, precipitating fixatives such as B5 have been known to produce unsatisfactory results in comparison with formalin when used for FISH. This study describes an effective nuclear isolation and FISH procedure for B5 and formalin fixed tissue, optimising the nuclear isolation step and nuclei pretreatments using tonsil and mantle cell lymphoma specimens. The protocol presented can be used to isolate nuclei and perform FISH on B5 or formalin fixed, paraffin wax embedded samples from a variety of tissue types.

  11. Switch from unboosted protease inhibitor to a single-tablet regimen containing rilpivirine improves cholesterol and triglycerides.

    PubMed

    Di Biagio, Antonio; Riccardi, Niccolò; Taramasso, Lucia; Capetti, Amedeo; Cenderello, Giovanni; Signori, Alessio; Vitiello, Paola; Guerra, Michele; de Socio, Giuseppe Vittorio; Cassola, Giovanni; Quirino, Tiziano; Viscoli, Claudio

    2016-11-01

    This study aimed to evaluate the efficacy, tolerability and potential savings of combined antiretroviral therapy (cART) simplification from an unboosted protease inhibitor (PI) regimen with atazanavir or fosamprenavir to a single-tablet regimen (STR) based on rilpivirine/emtricitabine/tenofovir disoproxil fumarate (RPV/FTC/TDF) among HIV-1-infected patients with HIV-1 RNA <50 copies/mL. This was a retrospective, multicentre, open-label, 12-week trial. Plasma HIV-1-RNA levels, CD4+ cell counts, cholesterol, triglycerides, bilirubin, glycaemia, creatinine and physical examination were performed at baseline and at scheduled follow-up. All patient costs were calculated and were estimated for 52 weeks of therapy. Fifty-one patients were enrolled [28 male (54.9%)]. At baseline, 30 patients (58.8%) were treated with FTC/TDF, 20 (39.2%) with abacavir/lamivudine and 1 (2.0%) with lamivudine/zidovudine. Thirty-three patients (64.7%) received atazanavir. All patients maintained HIV-RNA <50 copies/mL; the median CD4+ cell count remained stable. Mean triglycerides decreased from 124 mg/dL (range, 39-625) at enrolment to 108.7 mg/dL (range, 39-561) at study end (P = 0.25). At baseline, mean cholesterol was 172.8 ± 38.1 mg/dL and decreased to 161.9 ± 38.6 mg/dL (P = 0.038); likewise, median total bilirubin decreased from 1.07 mg/dL (range, 0.2-4.7) to 0.6 mg/dL (range, 0.13-3.1) (P <0.001). cART-related annual cost reduction with a STR was €3155.47 per patient (-24%). Non-cART patient management expenses were €402.68 vs. €299.10 for atazanavir or fosamprenavir and STR regimens, respectively. Switching to RPV/FTC/TDF from an unboosted PI in virologically suppressed HIV-infected patients is safe and is associated with a reduction in triglycerides, cholesterol and cART-related costs.

  12. The ESSA solution. [Electronic Switching Spherical Array

    NASA Technical Reports Server (NTRS)

    Hockensmith, R. P.; Stockton, R.

    1977-01-01

    ESSA (Electronic Switching Spherical Array) is a fixed truncated spherical antenna with its elements over the complete surface, conceived to satisfy many future antenna system requirements. Constant gain and beam shape throughout large volumetric coverage regions are the principle characteristics. In the present paper, the two existing types of ESSA are discussed. ESSA I is a simple nonphase correcting aperture approach characterized by light weight, low dc power consumption, gain between +7 and +14 dB, and 90% spherical coverage. ESSA II is a phase corrected aperture which would have very low sidelobe levels and improved gain over ESSA I (12 to 22 dB), but would be heavier and require more dc power.

  13. Training-Induced Improvement of Response Selection and Error Detection in Aging Assessed by Task Switching: Effects of Cognitive, Physical, and Relaxation Training

    PubMed Central

    Gajewski, Patrick D.; Falkenstein, Michael

    2012-01-01

    Cognitive control functions decline with increasing age. The present study examines if different types of group-based and trainer-guided training effectively enhance performance of older adults in a task switching task, and how this expected enhancement is reflected in changes of cognitive functions, as measured in electrophysiological brain activity (event-related potentials). One hundred forty-one healthy participants aged 65 years and older were randomly assigned to one of four groups: physical training (combined aerobic and strength training), cognitive training (paper–pencil and computer-aided), relaxation and wellness (social control group), and a control group that did not receive any intervention. Training sessions took place twice a week for 90 min for a period of 4 months. The results showed a greater improvement of performance for attendants of the cognitive training group compared to the other groups. This improvement was evident in a reduction of mixing costs in accuracy and intraindividual variability of speed, indexing improved maintenance of multiple task sets in working memory, and an enhanced coherence of neuronal processing. These findings were supported by event-related brain potentials which showed higher amplitudes in a number of potentials associated with response selection (N2), allocation of cognitive resources (P3b), and error detection (Ne). Taken together, our findings suggest neurocognitive plasticity of aging brains which can be stimulated by broad and multilayered cognitive training and assessed in detail by electrophysiological methods. PMID:22593740

  14. A Complex Inoculant of N2-Fixing, P- and K-Solubilizing Bacteria from a Purple Soil Improves the Growth of Kiwifruit (Actinidia chinensis) Plantlets

    PubMed Central

    Shen, Hong; He, Xinhua; Liu, Yiqing; Chen, Yi; Tang, Jianming; Guo, Tao

    2016-01-01

    Limited information is available if plant growth promoting bacteria (PGPB) can promote the growth of fruit crops through improvements in soil fertility. This study aimed to evaluate the capacity of PGPB, identified by phenotypic and 16S rRNA sequencing from a vegetable purple soil in Chongqing, China, to increase soil nitrogen (N), phosphorus (P), and potassium (K) availability and growth of kiwifruit (Actinidia chinensis). In doing so, three out of 17 bacterial isolates with a high capacity of N2-fixation (Bacillus amyloliquefaciens, XD-N-3), P-solubilization (B. pumilus, XD-P-1) or K-solubilization (B. circulans, XD-K-2) were mixed as a complex bacterial inoculant. A pot experiment then examined its effects of this complex inoculant on soil microflora, soil N2-fixation, P- and K-solubility and kiwifruit growth under four treatments. These treatments were (1) no-fertilizer and no-bacterial inoculant (Control), (2) no-bacterial inoculant and a full-rate of chemical NPK fertilizer (CF), (3) the complex inoculant (CI), and (4) a half-rate CF and full CI (1/2CF+CI). Results indicated that significantly greater growth of N2-fixing, P- and K-solubilizing bacteria among treatments ranked from greatest to least as under 1/2CF+CI ≈ CI > CF ≈ Control. Though generally without significant treatment differences in soil total N, P, or K, significantly greater soil available N, P, or K among treatments was, respectively, patterned as under 1/2CF+CI ≈ CI > CF ≈ Control, under 1/2CF+CI > CF > CI > Control or under 1/2CF+CI > CF ≈ CI > Control, indicating an improvement of soil fertility by this complex inoculant. In regards to plant growth, significantly greater total plant biomass and total N, P, and K accumulation among treatments were ranked as 1/2CF+CI ≈ CI > CF > Control. Additionally, significantly greater leaf polyphenol oxidase activity ranked as under CF > 1/2CF+CI ≈ Control ≈ CI, while leaf malondialdehyde contents as under Control > CI ≈ CF > 1/2CF

  15. A Complex Inoculant of N2-Fixing, P- and K-Solubilizing Bacteria from a Purple Soil Improves the Growth of Kiwifruit (Actinidia chinensis) Plantlets.

    PubMed

    Shen, Hong; He, Xinhua; Liu, Yiqing; Chen, Yi; Tang, Jianming; Guo, Tao

    2016-01-01

    Limited information is available if plant growth promoting bacteria (PGPB) can promote the growth of fruit crops through improvements in soil fertility. This study aimed to evaluate the capacity of PGPB, identified by phenotypic and 16S rRNA sequencing from a vegetable purple soil in Chongqing, China, to increase soil nitrogen (N), phosphorus (P), and potassium (K) availability and growth of kiwifruit (Actinidia chinensis). In doing so, three out of 17 bacterial isolates with a high capacity of N2-fixation (Bacillus amyloliquefaciens, XD-N-3), P-solubilization (B. pumilus, XD-P-1) or K-solubilization (B. circulans, XD-K-2) were mixed as a complex bacterial inoculant. A pot experiment then examined its effects of this complex inoculant on soil microflora, soil N2-fixation, P- and K-solubility and kiwifruit growth under four treatments. These treatments were (1) no-fertilizer and no-bacterial inoculant (Control), (2) no-bacterial inoculant and a full-rate of chemical NPK fertilizer (CF), (3) the complex inoculant (CI), and (4) a half-rate CF and full CI (1/2CF+CI). Results indicated that significantly greater growth of N2-fixing, P- and K-solubilizing bacteria among treatments ranked from greatest to least as under 1/2CF+CI ≈ CI > CF ≈ Control. Though generally without significant treatment differences in soil total N, P, or K, significantly greater soil available N, P, or K among treatments was, respectively, patterned as under 1/2CF+CI ≈ CI > CF ≈ Control, under 1/2CF+CI > CF > CI > Control or under 1/2CF+CI > CF ≈ CI > Control, indicating an improvement of soil fertility by this complex inoculant. In regards to plant growth, significantly greater total plant biomass and total N, P, and K accumulation among treatments were ranked as 1/2CF+CI ≈ CI > CF > Control. Additionally, significantly greater leaf polyphenol oxidase activity ranked as under CF > 1/2CF+CI ≈ Control ≈ CI, while leaf malondialdehyde contents as under Control > CI ≈ CF > 1/2CF

  16. New Fixed-Dose Combinations of Fenofibrate/Simvastatin Therapy Significantly Improve the Lipid Profile of High-Risk Patients with Mixed Dyslipidemia Versus Monotherapies.

    PubMed

    Foucher, Christelle; Aubonnet, Patrick; Reichert, Petr; Berli, Mario; Schaeffer, Axel; Calvo Vargas, Cesar Gonzalo; Lochocka, Anna; Belenky, Dmitry; Koch, Hans-Friedrich

    2015-12-01

    Guidelines propose additional therapy to statin to treat elevated triglycerides (TG) and low high-density lipoprotein cholesterol (HDLC) in dyslipidemic patients. We evaluated the effects of new fixed-dose combinations (FDC) of fenofibrate/simvastatin on plasma lipids versus simvastatin or fenofibrate monotherapies. Subjects with mixed dyslipidemia at high or very high cardiovascular risk on stable statin therapy for at least 3 months were included in a randomized, double-blind, active-control, parallel-group study. Patients were treated with FDC fenofibrate/simvastatin 145/20 mg or 145/40 mg, simvastatin 20 mg or 40 mg, or fenofibrate 145 mg for 12 weeks. Plasma lipids, C-reactive protein, and cystatin C were measured before and after treatments. Differences in % changes were compared between FDC fenofibrate/simvastatin and monotherapies. Significant differences between FDC fenofibrate/simvastatin and simvastatin monotherapies were observed for the % change of TG (LS mean difference [two-sided 95% CI]: -32.2% [-38.6%, -25.8%], P < 0.001) and HDL-C (7.5% [4.7%, 10.2%], P < 0.001). A significant difference between the FDC fenofibrate/simvastatin and fenofibrate was observed for LDLC % changes (-34.7% [-40.8%, -28.5%], P < 0.001). Significant differences between FDC fenofibrate/simvastatin and their respective monotherapies were also observed for Apo B and non-HDLC % changes. The FDC were well tolerated with a similar safety profile compared with monotherapies. FDC fenofibrate/simvastatin are effective and well-tolerated therapies to improve the TG and HDLC profile in high-risk patients with mixed dyslipidemia. © 2015 John Wiley & Sons Ltd.

  17. Improved results of LINE-1 methylation analysis in formalin-fixed, paraffin-embedded tissues with the application of a heating step during the DNA extraction process.

    PubMed

    Wen, Xianyu; Jeong, Seorin; Kim, Younghoon; Bae, Jeong Mo; Cho, Nam Yun; Kim, Jung Ho; Kang, Gyeong Hoon

    2017-01-01

    Formalin-fixed, paraffin-embedded (FFPE) tissues are important resources for profiling DNA methylation changes and for studying a variety of diseases. However, formalin fixation introduces inter-strand crosslinking, which might cause incomplete bisulfite conversion of unmethylated cytosines, which might lead to falsely elevated measurements of methylation levels in pyrosequencing assays. Long interspersed nucleotide element-1 (LINE-1) is a major constituent of repetitive transposable DNA elements, and its methylation is referred to correlates with global DNA methylation. To identify whether formalin fixation might impact the measured values of methylation in LINE-1 repetitive elements and whether prolonged heat-induced denaturation of DNA might reduce the artificial increases in measured values caused by formalin fixation, we analyzed paired fresh-frozen (FF) and FFPE xenograft tissue samples for their methylation levels in LINE-1 using a pyrosequencing assay. To further confirm the effect of a heating step in the measurement of LINE-1 or single gene methylation levels, we analyzed FFPE tissue samples of gastric cancer and colorectal cancer for their methylation status in LINE-1 and eight single genes, respectively. Formalin fixation led to an increase in the measured values of LINE-1 methylation regardless of the duration of fixation. Prolonged heating of the DNA at 95 °C for 30 min before bisulfite conversion was found (1) to decrease the discrepancy in the measured values between the paired FF and FFPE tissue samples, (2) to decrease the standard deviation of the measured value of LINE-1 methylation levels in FFPE tissue samples of gastric cancer, and (3) to improve the performance in the measurement of single gene methylation levels in FFPE tissue samples of colorectal cancer. Formalin fixation leads to artificial increases in the measured values of LINE-1 methylation, and the application of prolonged heating of DNA samples decreases the discrepancy in the

  18. Improve the Performance of Orthogonal ASK/DPSK Optical Label Switching by DC-Balanced Line Encoding

    NASA Astrophysics Data System (ADS)

    Chi, Nan; Xu, Lin; Zhang, Jianfeng; Holm-Nielsen, Pablo V.; Peucheret, Christophe; Yu, Siyuan; Jeppesen, Palle

    2006-03-01

    Orthogonal amplitude shift keying/differential phase-shift keying (ASK/DPSK) labeling is a promising approach to ultrahigh packet-rate routing and forwarding in the optical layer. However, the limitation on the payload extinction ratio (ER) is a detrimental effect for network scalability and transparency. This paper presents theoretical and experimental studies of ASK/DPSK labeling. It proposes that dc-balanced 8B10B coding can greatly improve ER tolerance, which in turn leads to better system performance. By using the 8B10B coding method, the paper demonstrates transmission and optical label swapping for a 40 Gb/s ASK payload and a 2.5 Gb/s DPSK label with an overall power penalty of 3.3 dB for the payload and 0.3 dB for the label. The experimental results also show that the ER is allowed to be as high as 12 dB.

  19. Large arrays and properties of 3-terminal graphene nanoelectromechanical switches.

    PubMed

    Liu, Xinghui; Suk, Ji Won; Boddeti, Narasimha G; Cantley, Lauren; Wang, Luda; Gray, Jason M; Hall, Harris J; Bright, Victor M; Rogers, Charles T; Dunn, Martin L; Ruoff, Rodney S; Bunch, J Scott

    2014-03-12

    Large arrays of 3-terminal nanoelectromechanical graphene switches are fabricated. The switch is designed with a novel geometry that leads to low actuation voltages and improved mechanical integrity, while reducing adhesion forces, which improves the reliability of the switch. A finite element model including non-linear electromechanics is used to simulate the switching behavior and to deduce a scaling relation between the switching voltage and device dimensions.

  20. Power Quality Improvement in Bridgeless Ac-Dc Converter Based Multi-output Switched Mode Power Supply

    NASA Astrophysics Data System (ADS)

    Singh, Shihka; Singh, Bhim; Bhuvaneswari, G.; Bist, Vashist

    2014-12-01

    Computer power supplies are required to have multiple isolated regulated dc voltages with low ripple content and high input power factor at the utility interface. A dc-dc converter is used for obtaining these isolated multi-output dc voltages with excellent regulation. In this paper, a non-isolated ac-dc converter is proposed as the first stage converter to obtain a regulated dc output rather than using a simple uncontrolled diode bridge rectifier at the front end. A dc-dc converter is used at the second stage that has a high frequency transformer with multiple secondary windings to obtain different dc voltage levels at the output. The proposed bridgeless converter based power supply is designed using fundamental design equations, and different component values are calculated. Extensive simulations are carried out to demonstrate the improved performance of the proposed bridgeless converter based multi-output computer power supply at varying source voltages and load conditions. Experimental validation of the power supply is carried on a developed hardware prototype, and the test results are compared with the simulated performance for design verification.

  1. Improving the Sustainability of Oak Woodland Forage and Productivity in San Diego County Through the Exploration for and Introduction of Nitrogen Fixing Annual Legumes

    Treesearch

    Walter L. Graves; Melvin D. Rumbaugh; Wesley M. Jarrell

    1991-01-01

    The oak woodlands of San Diego County are below their potential productivity due to the low levels of the most needed plant nutrient, nitrogen, associated with the common soils of this zone. Atmospheric nitrogen fixing legumes could address this deficiency. However, because of limiting environmental constraints, adapted commercial legume cultivars have not been...

  2. Impact of electrically formed interfacial layer and improved memory characteristics of IrOx/high-κx/W structures containing AlOx, GdOx, HfOx, and TaOx switching materials

    PubMed Central

    2013-01-01

    Improved switching characteristics were obtained from high-κ oxides AlOx, GdOx, HfOx, and TaOx in IrOx/high-κx/W structures because of a layer that formed at the IrOx/high-κx interface under external positive bias. The surface roughness and morphology of the bottom electrode in these devices were observed by atomic force microscopy. Device size was investigated using high-resolution transmission electron microscopy. More than 100 repeatable consecutive switching cycles were observed for positive-formatted memory devices compared with that of the negative-formatted devices (only five unstable cycles) because it contained an electrically formed interfacial layer that controlled ‘SET/RESET’ current overshoot. This phenomenon was independent of the switching material in the device. The electrically formed oxygen-rich interfacial layer at the IrOx/high-κx interface improved switching in both via-hole and cross-point structures. The switching mechanism was attributed to filamentary conduction and oxygen ion migration. Using the positive-formatted design approach, cross-point memory in an IrOx/AlOx/W structure was fabricated. This cross-point memory exhibited forming-free, uniform switching for >1,000 consecutive dc cycles with a small voltage/current operation of ±2 V/200 μA and high yield of >95% switchable with a large resistance ratio of >100. These properties make this cross-point memory particularly promising for high-density applications. Furthermore, this memory device also showed multilevel capability with a switching current as low as 10 μA and a RESET current of 137 μA, good pulse read endurance of each level (>105 cycles), and data retention of >104 s at a low current compliance of 50 μA at 85°C. Our improvement of the switching characteristics of this resistive memory device will aid in the design of memory stacks for practical applications. PMID:24011235

  3. Cognitive Training Sustainably Improves Executive Functioning in Middle-Aged Industry Workers Assessed by Task Switching: A Randomized Controlled ERP Study

    PubMed Central

    Gajewski, Patrick D.; Freude, Gabriele; Falkenstein, Michael

    2017-01-01

    Recently, we reported results of a cross-sectional study investigating executive functions in dependence of aging and type of work. That study showed deficits in performance and electrophysiological activity in middle-aged workers with long-term repetitive and unchallenging work. Based on these findings, we conducted a longitudinal study that aimed at ameliorating these cognitive deficits by means of a trainer-guided cognitive training (CT) in 57 further middle-aged workers with repetitive type of work from the same factory. This study was designed as a randomized controlled trail with pre- (t1), post- (t2), and a 3-month follow-up (t3) measure. The waiting control group was trained between t2 and t3. The training lasted 3 months (20 sessions) and was evaluated with the same task switching paradigm used in the previous cross-sectional study. The CT improved performance in accuracy at the behavioral level and affected the electrophysiological correlates of retrieval of stimulus-response sets (P2), response selection (N2), and error detection (Ne), thus unveiling the neuronal background of the behavioral effects. The same training effects were observed in the waiting control group after CT at t3. Moreover, at t3, most of the behavioral and electrophysiological training-induced changes were found stable. Hence, CT appears to be an important intervention for compensating cognitive deficits in executive functions in middle-aged employees with cognitively unchallenging work. PMID:28275347

  4. Cognitive Training Sustainably Improves Executive Functioning in Middle-Aged Industry Workers Assessed by Task Switching: A Randomized Controlled ERP Study.

    PubMed

    Gajewski, Patrick D; Freude, Gabriele; Falkenstein, Michael

    2017-01-01

    Recently, we reported results of a cross-sectional study investigating executive functions in dependence of aging and type of work. That study showed deficits in performance and electrophysiological activity in middle-aged workers with long-term repetitive and unchallenging work. Based on these findings, we conducted a longitudinal study that aimed at ameliorating these cognitive deficits by means of a trainer-guided cognitive training (CT) in 57 further middle-aged workers with repetitive type of work from the same factory. This study was designed as a randomized controlled trail with pre- (t1), post- (t2), and a 3-month follow-up (t3) measure. The waiting control group was trained between t2 and t3. The training lasted 3 months (20 sessions) and was evaluated with the same task switching paradigm used in the previous cross-sectional study. The CT improved performance in accuracy at the behavioral level and affected the electrophysiological correlates of retrieval of stimulus-response sets (P2), response selection (N2), and error detection (Ne), thus unveiling the neuronal background of the behavioral effects. The same training effects were observed in the waiting control group after CT at t3. Moreover, at t3, most of the behavioral and electrophysiological training-induced changes were found stable. Hence, CT appears to be an important intervention for compensating cognitive deficits in executive functions in middle-aged employees with cognitively unchallenging work.

  5. Unipolar poling-induced high switching speed and improved imprint behaviors for poly(vinylidene fluoride-trifluoroethylene) copolymer ultrathin films

    NASA Astrophysics Data System (ADS)

    Hou, Ying; Lü, Zhaoyue; Pu, Tiansong; Zhang, Yuan; Meng, Xiangjian; Xu, Haisheng

    2013-12-01

    The polarization switching and imprint behaviors with different pulse and unipolar poling processes for ferroelectric poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) copolymer ultrathin films have been studied. Compared with results for samples only through the certain protocol we studied previously, the much faster switching speed and lower voltage shift are observed for films with certain protocol as well as certain unipolar poling. The analyses show that these properties are strongly dependent on the directions of the switching and unipolar poling field. The results provide another effective route to design the optimum protocol for ferroelectric random access memory based on P(VDF-TrFE) copolymer ultrathin film.

  6. Improved stability of a class of switched neutral systems via Lyapunov-Krasovskii functionals and an average dwell-time scheme

    NASA Astrophysics Data System (ADS)

    Li, Tai-Fang; Dimirovski, Georgi M.; Liu, Yanyan; Zhao, Jun

    2013-06-01

    This article is concerned with the stability analysis for a class of switched neutral systems with mixed time-varying delays. The upper bound of derivative of the discrete time-varying delay is not restricted to one. A delay-dependent criterion of exponential stability under switching signals with an average dwell time is developed by employing free weighting matrices. The criterion is given in the form of linear matrix inequality. A state decay estimation for the switched system is explicitly given by considering the individual rate of decay of state for each subsystem. Two simulation examples are given to illustrate the effectiveness of the proposed method.

  7. Differences in Nighttime and Daytime Ambulatory Blood Pressure When Diurnal Periods Are Defined by Self-report, Fixed-Times and Actigraphy: Improving the Detection of Hypertension Study

    PubMed Central

    BOOTH, John N.; MUNTNER, Paul; ABDALLA, Marwah; DIAZ, Keith M.; VIERA, Anthony J.; REYNOLDS, Kristi; SCHWARTZ, Joseph E.; SHIMBO, Daichi

    2016-01-01

    Objectives To determine whether defining diurnal periods by self-report, fixed-time or actigraphy produce different estimates of nighttime and daytime ambulatory blood pressure (ABP). Methods Over a median of 28 days, 330 participants completed two 24-hour ABP and actigraphy monitoring periods with sleep diaries. Fixed nighttime and daytime periods were defined as 00:00–06:00 and 10:00–20:00, respectively. Using the first ABP period, within-individual differences for mean nighttime and daytime ABP and Kappa statistics for nighttime and daytime hypertension (systolic/diastolic ABP ≥120/70 mmHg and ≥135/85 mmHg, respectively) were estimated comparing self-report, fixed-time or actigraphy for defining diurnal periods. Reproducibility of ABP was also estimated. Results Within-individual mean differences in nighttime systolic ABP were small, suggesting little bias, when comparing the three approaches used to define diurnal periods. The distribution of differences, represented by 95% confidence intervals (CI), in nighttime systolic and diastolic ABP and daytime systolic and diastolic ABP was narrowest for self-report versus actigraphy. For example, mean differences (95% CI) in nighttime systolic ABP for self-report versus fixed-time was −0.53 (−6.61,+5.56) mmHg, self-report versus actigraphy was 0.91 (−3.61,+5.43) mmHg and fixed-time versus actigraphy was 1.43 (−5.59,+8.46) mmHg. Agreement for nighttime and daytime hypertension was highest for self-report versus actigraphy: Kappa statistic (95% CI)=0.91 (0.86,0.96) and 1.00 (0.98,1.00), respectively. The reproducibility of mean ABP and hypertension categories was similar using each approach. Conclusion Given the high agreement with actigraphy, these data support using self-report to define diurnal periods on ABP monitoring. Further, the use of fixed-time periods may be a reasonable alternative approach. PMID:26867054

  8. Safety and tolerability of fixed antihypertensive combinations in blood pressure control: focus on olmesartan medoxomil and amlodipine combination

    PubMed Central

    Uddin, Ijlal; Aslam, Shakil

    2010-01-01

    Hypertension is a major health problem worldwide and remains underdiagnosed and undertreated. Although public awareness and control of hypertension have improved over the last decade, only one-third of hypertensive patients achieve the rather conservative blood pressure (BP) goal of <140/90 mmHg. Most hypertensive patients require more than one drug for optimum BP control. Expert panels recommend use of combination therapy with two or more medications for Stage 2 and higher hypertension and in high-risk patients. However, the use of multiple drugs reduces patient compliance. Fixed-dose combination therapy helps improve patient compliance and thus achieve the target BP. Dose titration of the individual constituent drugs is recommended before switching to an equivalent fixed-dose combination. Randomized, controlled trials have shown that the fixed-dose combination of amlodipine–olmesartan medoxomil is more effective in lowering BP than monotherapy with either of these agents, with a similar side effect profile. PMID:21949631

  9. Magnetic switching

    SciTech Connect

    Birx, D.; Cook, E.; Hawkins, S.; Poor, S.; Reginato, L.; Schmidt, J.; Smith, M.

    1983-06-01

    The paper discusses the development program in magnetic switching which was aimed at solving the rep-rate and reliability limitations of the ATA spark gaps. The end result has been a prototype physically very similar to the present Advanced Test Accelerator (ATA) pulse power unit but vastly superior in performance. This prototype, which is easily adaptable to the existing systems, has achieved a burst rep-rate of 20 kHz and an output voltage of 500 kV. A one-on-one substitution of the existing pulse power module would result in a 100 MeV accelerator. Furthermore, the high efficiency of the magnetic pulse compression stages has allowed CW operation of the prototype at one kilohertz opening up other applications for the pulse power. Performance and design details will be described.

  10. Endurance and Cycle-to-cycle Uniformity Improvement in Tri-Layered CeO2/Ti/CeO2 Resistive Switching Devices by Changing Top Electrode Material

    NASA Astrophysics Data System (ADS)

    Rana, Anwar Manzoor; Akbar, Tahira; Ismail, Muhammad; Ahmad, Ejaz; Hussain, Fayyaz; Talib, Ijaz; Imran, Muhammad; Mehmood, Khalid; Iqbal, Khalid; Nadeem, M. Younus

    2017-01-01

    Resistance switching characteristics of CeO2/Ti/CeO2 tri-layered films sandwiched between Pt bottom electrode and two different top electrodes (Ti and TaN) with different work functions have been investigated. RRAM memory cells composed of TaN/CeO2/Ti/CeO2/Pt reveal better resistive switching performance instead of Ti/CeO2/Ti/CeO2/Pt memory stacks. As compared to the Ti/CeO2 interface, much better ability of TaN/CeO2 interface to store and exchange plays a key role in the RS performance improvement, including lower forming/SET voltages, large memory window (~102) and no significant data degradation during endurance test of >104 switching cycles. The formation of TaON thinner interfacial layer between TaN TE and CeO2 film is found to be accountable for improved resistance switching behavior. Partial charge density of states is analyzed using density functional theory. It is found that the conductive filaments formed in CeO2 based devices is assisted by interstitial Ti dopant. Better stability and reproducibility in cycle-to-cycle (C2C) resistance distribution and Vset/Vreset uniformity were achieved due to the modulation of current conduction mechanism from Ohmic in low field region to Schottky emission in high field region.

  11. Endurance and Cycle-to-cycle Uniformity Improvement in Tri-Layered CeO2/Ti/CeO2 Resistive Switching Devices by Changing Top Electrode Material.

    PubMed

    Rana, Anwar Manzoor; Akbar, Tahira; Ismail, Muhammad; Ahmad, Ejaz; Hussain, Fayyaz; Talib, Ijaz; Imran, Muhammad; Mehmood, Khalid; Iqbal, Khalid; Nadeem, M Younus

    2017-01-12

    Resistance switching characteristics of CeO2/Ti/CeO2 tri-layered films sandwiched between Pt bottom electrode and two different top electrodes (Ti and TaN) with different work functions have been investigated. RRAM memory cells composed of TaN/CeO2/Ti/CeO2/Pt reveal better resistive switching performance instead of Ti/CeO2/Ti/CeO2/Pt memory stacks. As compared to the Ti/CeO2 interface, much better ability of TaN/CeO2 interface to store and exchange plays a key role in the RS performance improvement, including lower forming/SET voltages, large memory window (~10(2)) and no significant data degradation during endurance test of >10(4) switching cycles. The formation of TaON thinner interfacial layer between TaN TE and CeO2 film is found to be accountable for improved resistance switching behavior. Partial charge density of states is analyzed using density functional theory. It is found that the conductive filaments formed in CeO2 based devices is assisted by interstitial Ti dopant. Better stability and reproducibility in cycle-to-cycle (C2C) resistance distribution and Vset/Vreset uniformity were achieved due to the modulation of current conduction mechanism from Ohmic in low field region to Schottky emission in high field region.

  12. Endurance and Cycle-to-cycle Uniformity Improvement in Tri-Layered CeO2/Ti/CeO2 Resistive Switching Devices by Changing Top Electrode Material

    PubMed Central

    Rana, Anwar Manzoor; Akbar, Tahira; Ismail, Muhammad; Ahmad, Ejaz; Hussain, Fayyaz; Talib, Ijaz; Imran, Muhammad; Mehmood, Khalid; Iqbal, Khalid; Nadeem, M. Younus

    2017-01-01

    Resistance switching characteristics of CeO2/Ti/CeO2 tri-layered films sandwiched between Pt bottom electrode and two different top electrodes (Ti and TaN) with different work functions have been investigated. RRAM memory cells composed of TaN/CeO2/Ti/CeO2/Pt reveal better resistive switching performance instead of Ti/CeO2/Ti/CeO2/Pt memory stacks. As compared to the Ti/CeO2 interface, much better ability of TaN/CeO2 interface to store and exchange plays a key role in the RS performance improvement, including lower forming/SET voltages, large memory window (~102) and no significant data degradation during endurance test of >104 switching cycles. The formation of TaON thinner interfacial layer between TaN TE and CeO2 film is found to be accountable for improved resistance switching behavior. Partial charge density of states is analyzed using density functional theory. It is found that the conductive filaments formed in CeO2 based devices is assisted by interstitial Ti dopant. Better stability and reproducibility in cycle-to-cycle (C2C) resistance distribution and Vset/Vreset uniformity were achieved due to the modulation of current conduction mechanism from Ohmic in low field region to Schottky emission in high field region. PMID:28079056

  13. "Platform switching": serendipity.

    PubMed

    Kalavathy, N; Sridevi, J; Gehlot, Roshni; Kumar, Santosh

    2014-01-01

    Implant dentistry is the latest developing field in terms of clinical techniques, research, material science and oral rehabilitation. Extensive work is being done to improve the designing of implants in order to achieve better esthetics and function. The main drawback with respect to implant restoration is achieving good osseointegration along with satisfactory stress distribution, which in turn will improve the prognosis of implant prosthesis by reducing the crestal bone loss. Many concepts have been developed with reference to surface coating of implants, surgical techniques for implant placement, immediate and delayed loading, platform switching concept, etc. This article has made an attempt to review the concept of platform switching was in fact revealed accidentally due to the nonavailability of the abutment appropriate to the size of the implant placed. A few aspect of platform switching, an upcoming idea to reduce crestal bone loss have been covered. The various methods used for locating and preparing the data were done through textbooks, Google search and related articles.

  14. Fixed Sagittal Plane Imbalance

    PubMed Central

    Savage, Jason W.; Patel, Alpesh A.

    2014-01-01

    Study Design Literature review. Objective To discuss the evaluation and management of fixed sagittal plane imbalance. Methods A comprehensive literature review was performed on the preoperative evaluation of patients with sagittal plane malalignment, as well as the surgical strategies to address sagittal plane deformity. Results Sagittal plane imbalance is often caused by de novo scoliosis or iatrogenic flat back deformity. Understanding the etiology and magnitude of sagittal malalignment is crucial in realignment planning. Objective parameters have been developed to guide surgeons in determining how much correction is needed to achieve favorable outcomes. Currently, the goals of surgery are to restore a sagittal vertical axis < 5 cm, pelvic tilt < 20 degrees, and lumbar lordosis equal to pelvic incidence ± 9 degrees. Conclusion Sagittal plane malalignment is an increasingly recognized cause of pain and disability. Treatment of sagittal plane imbalance varies according to the etiology, location, and severity of the deformity. Fixed sagittal malalignment often requires complex reconstructive procedures that include osteotomy correction. Reestablishing harmonious spinopelvic alignment is associated with significant improvement in health-related quality-of-life outcome measures and patient satisfaction. PMID:25396111

  15. Fixed sagittal plane imbalance.

    PubMed

    Savage, Jason W; Patel, Alpesh A

    2014-12-01

    Study Design Literature review. Objective To discuss the evaluation and management of fixed sagittal plane imbalance. Methods A comprehensive literature review was performed on the preoperative evaluation of patients with sagittal plane malalignment, as well as the surgical strategies to address sagittal plane deformity. Results Sagittal plane imbalance is often caused by de novo scoliosis or iatrogenic flat back deformity. Understanding the etiology and magnitude of sagittal malalignment is crucial in realignment planning. Objective parameters have been developed to guide surgeons in determining how much correction is needed to achieve favorable outcomes. Currently, the goals of surgery are to restore a sagittal vertical axis < 5 cm, pelvic tilt < 20 degrees, and lumbar lordosis equal to pelvic incidence ± 9 degrees. Conclusion Sagittal plane malalignment is an increasingly recognized cause of pain and disability. Treatment of sagittal plane imbalance varies according to the etiology, location, and severity of the deformity. Fixed sagittal malalignment often requires complex reconstructive procedures that include osteotomy correction. Reestablishing harmonious spinopelvic alignment is associated with significant improvement in health-related quality-of-life outcome measures and patient satisfaction.

  16. Communication: Toward an improved control of the fixed-node error in quantum Monte Carlo: The case of the water molecule.

    PubMed

    Caffarel, Michel; Applencourt, Thomas; Giner, Emmanuel; Scemama, Anthony

    2016-04-21

    All-electron Fixed-node DiffusionMonte Carlo calculations for the nonrelativistic ground-state energy of the water molecule at equilibrium geometry are presented. The determinantal part of the trial wavefunction is obtained from a selected Configuration Interaction calculation[Configuration Interaction using a Perturbative Selection done Iteratively (CIPSI) method] including up to about 1.4 × 10(6) of determinants. Calculations are made using the cc-pCVnZ family of basis sets, with n = 2 to 5. In contrast with most quantum Monte Carlo works no re-optimization of the determinantal part in presence of a Jastrow is performed. For the largest cc-pCV5Z basis set the lowest upper bound for the ground-state energy reported so far of -76.437 44(18) is obtained. The fixed-node energy is found to decrease regularly as a function of the cardinal numbern and the Complete Basis Set limit associated with exact nodes is easily extracted. The resulting energy of -76.438 94(12) - in perfect agreement with the best experimentally derived value - is the most accurate theoretical estimate reported so far. We emphasize that employing selected configuration interactionnodes of increasing quality in a given family of basis sets may represent a simple, deterministic, reproducible, and systematic way of controlling the fixed-node error in diffusionMonte Carlo.

  17. Communication: Toward an improved control of the fixed-node error in quantum Monte Carlo: The case of the water molecule

    NASA Astrophysics Data System (ADS)

    Caffarel, Michel; Applencourt, Thomas; Giner, Emmanuel; Scemama, Anthony

    2016-04-01

    All-electron Fixed-node Diffusion Monte Carlo calculations for the nonrelativistic ground-state energy of the water molecule at equilibrium geometry are presented. The determinantal part of the trial wavefunction is obtained from a selected Configuration Interaction calculation [Configuration Interaction using a Perturbative Selection done Iteratively (CIPSI) method] including up to about 1.4 × 106 of determinants. Calculations are made using the cc-pCVnZ family of basis sets, with n = 2 to 5. In contrast with most quantum Monte Carlo works no re-optimization of the determinantal part in presence of a Jastrow is performed. For the largest cc-pCV5Z basis set the lowest upper bound for the ground-state energy reported so far of -76.437 44(18) is obtained. The fixed-node energy is found to decrease regularly as a function of the cardinal number n and the Complete Basis Set limit associated with exact nodes is easily extracted. The resulting energy of -76.438 94(12) — in perfect agreement with the best experimentally derived value — is the most accurate theoretical estimate reported so far. We emphasize that employing selected configuration interaction nodes of increasing quality in a given family of basis sets may represent a simple, deterministic, reproducible, and systematic way of controlling the fixed-node error in diffusion Monte Carlo.

  18. Normal and abnormal function of the pacemaker magnetic reed switch.

    PubMed

    Driller, J; Barold, S S; Parsonnet, V

    1976-01-01

    Application of the special test magnet over a demand pacemaker actuates a magnetic reed switch which converts the pacemaker to fixed-rate pacing. The magnetic reed switch is a simple and generally very reliable component. This review discusses the normal and abnormal functions of the pacemaker magnetic reed switch. An understanding of the theoretical and practical aspects of this subject is important in the overall management of patients with implanted pacemakers.

  19. Using estrus detection patches to optimally time insemination improved pregnancy risk in suckled beef cows enrolled in a fixed-time artificial insemination program.

    PubMed

    Hill, S L; Grieger, D M; Olson, K C; Jaeger, J R; Dahlen, C R; Bridges, G A; Dantas, F; Larson, J E; Muth-Spurlock, A M; Ahola, J K; Fischer, M C; Perry, G A; Larimore, E L; Steckler, T L; Whittier, W D; Currin, J F; Stevenson, J S

    2016-09-01

    A multilocation study examined pregnancy risk (PR) after delaying AI in suckled beef cows from 60 to 75 h when estrus had not been detected by 60 h in response to a 7-d CO-Synch + progesterone insert (CIDR) timed AI (TAI) program (d -7: CIDR insert concurrent with an injection of GnRH; d 0: PGF injection and removal of CIDR insert; and GnRH injection at TAI [60 or 75 h after CIDR removal]). A total of 1,611 suckled beef cows at 15 locations in 9 states (CO, IL, KS, MN, MS, MT, ND, SD, and VA) were enrolled. Before applying the fixed-time AI program, BCS was assessed, and blood samples were collected. Estrus was defined to have occurred when an estrus detection patch was >50% colored (activated). Pregnancy was determined 35 d after AI via transrectal ultrasound. Cows ( = 746) detected in estrus by 60 h (46.3%) after CIDR removal were inseminated and treated with GnRH at AI (Control). Remaining nonestrous cows were allocated within location to 3 treatments on the basis of parity and days postpartum: 1) GnRH injection and AI at 60 h (early-early = EE; = 292), 2) GnRH injection at 60 h and AI at 75 h (early-delayed = ED; = 282), or 3) GnRH injection and AI at 75 h (delayed-delayed = DD; = 291). Control cows had a greater ( < 0.01) PR (64.2%) than other treatments (EE = 41.7%, ED = 52.8%, DD = 50.0%). Use of estrus detection patches to delay AI in cows not in estrus by 60 h after CIDR insert removal (ED and DD treatments) increased ( < 0.05) PR to TAI when compared with cows in the EE treatment. More ( < 0.001) cows that showed estrus by 60 h conceived to AI at 60 h than those not showing estrus (64.2% vs. 48.1%). Approximately half (49.2%) of the cows not in estrus by 60 h had activated patches by 75 h, resulting in a greater ( < 0.05) PR than their nonestrous herd mates in the EE (46.1% vs. 34.5%), ED (64.2% vs. 39.2%), and DD (64.8% vs. 31.5%) treatments, respectively. Overall, cows showing estrus by 75 h (72.7%) had greater ( < 0.001) PR to AI (61.3% vs. 37.9%) than

  20. Plasma Switch Development.

    DTIC Science & Technology

    1984-06-08

    switch :9 (1) the low-pressure gas switch 17 (2) the surface flashover switch ,18 (3) the thyrtron,’ŕ (4) the high pressure...spark gap, (5) the magnetic switch .’ 9 20 and (6) the ECS. The ongoing research for both the low pressure gas and surface flashover closing- switches has... investigations into optimizing gas mixtures for opening switch applications 1 ’"’"’’’a𔃻 ; and a preliminary study of the discharge stabili-

  1. Adaptive control under arbitrary switching for a class of switched nonlinear systems with nonlinear parameterisation

    NASA Astrophysics Data System (ADS)

    Wang, C. Y.; Jiao, X. H.

    2015-10-01

    This paper is devoted to discuss arbitrarily switching control problem for a class of nonlinearly parameterised nonlinear switched systems. Compared with the existing results, improvements are that a systematic procedure is given for an explicit construction of a common smooth adaptive controller independent of the switching signals. Meanwhile, the developed design method can be extended to the adaptive arbitrarily switching stabilisation problem for a class of cascade switched nonlinear systems. The theoretical analysis is presented for the Lyapunov stability of the resulting closed-loop switched system and the convergence of the original switched system states at the equilibrium under arbitrary switching. Moreover, the effectiveness and feasibility of the developed method are demonstrated by both a numerical example and a chemical system.

  2. Switch Transcripts in Immunoglobulin Class Switching

    NASA Astrophysics Data System (ADS)

    Lorenz, Matthias; Jung, Steffen; Radbruch, Andreas

    1995-03-01

    B cells can exchange gene segments for the constant region of the immunoglobulin heavy chain, altering the class and effector function of the antibodies that they produce. Class switching is directed to distinct classes by cytokines, which induce transcription of the targeted DNA sequences. These transcripts are processed, resulting in spliced "switch" transcripts. Switch recombination can be directed to immunoglobulin G1 (IgG1) by the heterologous human metallothionein II_A promoter in mutant mice. Induction of the structurally conserved, spliced switch transcripts is sufficient to target switch recombination to IgG1, whereas transcription alone is not.

  3. Switching to second-generation tyrosine kinase inhibitor improves the response and outcome of frontline imatinib-treated patients with chronic myeloid leukemia with more than 10% of BCR-ABL/ABL ratio at 3 months

    PubMed Central

    Casado, Luis-Felipe; García-Gutiérrez, José-Valentín; Massagué, Isabel; Giraldo, Pilar; Pérez-Encinas, Manuel; de Paz, Raquel; Martínez-López, Joaquín; Bautista, Guiomar; Osorio, Santiago; Requena, María-José; Palomera, Luis; Peñarrubia, María-Jesús; Calle, Carmen; Hernández-Rivas, José-Ángel; Burgaleta, Carmen; Maestro, Begoña; García-Ormeña, Nuria; Steegmann, Juan-Luis

    2015-01-01

    Chronic myeloid leukemia patients display heterogeneous responses to imatinib. Survival depends on baseline clinical characteristics (including prognostic scoring systems) and on early response (such as >10% BCR-ABL/ABL ratio at 3 months of therapy). The results of switching to second-generation tyrosine kinase inhibitors (2GTKIs) may contain a bias since, in the majority of these studies, patients who switch treatment due to intolerance or failure are censored or excluded. We analyzed the Spanish Registry data on switching in an intention-to-treat analysis of patients in standard clinical practice. Switching to 2GTKIs improves responses from 45% to 75% of complete cytogenetic response (CCyR) and from 15% to 45% of major molecular response (MMR) in the group without molecular response 1 (MR1) at 3 months and from 70% to 87% in CCyR and from 52% to 87% in MMR in the group with MR1. The final response rate is poorer in the group with no MR1 at 3 months. Nevertheless, the differences in the rates of response were not translated into differences in major events (transformations or deaths), and the final progression-free survival and overall survival were similar. PMID:25756742

  4. Switching to second-generation tyrosine kinase inhibitor improves the response and outcome of frontline imatinib-treated patients with chronic myeloid leukemia with more than 10% of BCR-ABL/ABL ratio at 3 months.

    PubMed

    Casado, Luis-Felipe; García-Gutiérrez, José-Valentín; Massagué, Isabel; Giraldo, Pilar; Pérez-Encinas, Manuel; de Paz, Raquel; Martínez-López, Joaquín; Bautista, Guiomar; Osorio, Santiago; Requena, María-José; Palomera, Luis; Peñarrubia, María-Jesús; Calle, Carmen; Hernández-Rivas, José-Ángel; Burgaleta, Carmen; Maestro, Begoña; García-Ormeña, Nuria; Steegmann, Juan-Luis

    2015-07-01

    Chronic myeloid leukemia patients display heterogeneous responses to imatinib. Survival depends on baseline clinical characteristics (including prognostic scoring systems) and on early response (such as >10% BCR-ABL/ABL ratio at 3 months of therapy). The results of switching to second-generation tyrosine kinase inhibitors (2GTKIs) may contain a bias since, in the majority of these studies, patients who switch treatment due to intolerance or failure are censored or excluded. We analyzed the Spanish Registry data on switching in an intention-to-treat analysis of patients in standard clinical practice. Switching to 2GTKIs improves responses from 45% to 75% of complete cytogenetic response (CCyR) and from 15% to 45% of major molecular response (MMR) in the group without molecular response 1 (MR1) at 3 months and from 70% to 87% in CCyR and from 52% to 87% in MMR in the group with MR1. The final response rate is poorer in the group with no MR1 at 3 months. Nevertheless, the differences in the rates of response were not translated into differences in major events (transformations or deaths), and the final progression-free survival and overall survival were similar.

  5. Final Report: Cooling Seasonal Energy and Peak Demand Impacts of Improved Duct Insulation on Fixed-Capacity (SEER 13) and Variable-Capacity (SEER 22) Heat Pumps

    SciTech Connect

    Withers, C.; Cummings, J.; Nigusse, B.

    2016-09-01

    A new generation of full variable-capacity, central, ducted air-conditioning (AC) and heat pump units has come on the market, and they promise to deliver increased cooling (and heating) efficiency. They are controlled differently than standard single-capacity (fixed-capacity) systems. Instead of cycling on at full capacity and then cycling off when the thermostat is satisfied, they can vary their capacity over a wide range (approximately 40% to 118% of nominal full capacity), thus staying “on” for up to twice as many hours per day compared to fixed-capacity systems of the same nominal capacity. The heating and cooling capacity is varied by adjusting the indoor fan air flow rate, compressor, and refrigerant flow rate as well as the outdoor unit fan air flow rate. Note that two-stage AC or heat pump systems were not evaluated in this research effort. The term dwell is used to refer to the amount of time distributed air spends inside ductwork during space-conditioning cycles. Longer run times mean greater dwell time and therefore greater exposure to conductive gains and losses.

  6. Final Report: Cooling Seasonal Energy and Peak Demand Impacts of Improved Duct Insulation on Fixed-Capacity (SEER 13) and Variable-Capacity (SEER 22) Heat Pumps

    SciTech Connect

    C. Withers; Cummings, J.; Nigusse, B.

    2016-09-08

    A new generation of full variable-capacity, central, ducted air-conditioning (AC) and heat pump units has come on the market, and they promise to deliver increased cooling (and heating) efficiency. They are controlled differently than standard single-capacity (fixed-capacity) systems. Instead of cycling on at full capacity and then cycling off when the thermostat is satisfied, they can vary their capacity over a wide range (approximately 40% to 118% of nominal full capacity), thus staying “on” for up to twice as many hours per day compared to fixed-capacity systems of the same nominal capacity. The heating and cooling capacity is varied by adjusting the indoor fan air flow rate, compressor, and refrigerant flow rate as well as the outdoor unit fan air flow rate. Note that two-stage AC or heat pump systems were not evaluated in this research effort. The term dwell is used to refer to the amount of time distributed air spends inside ductwork during space-conditioning cycles. Longer run times mean greater dwell time and therefore greater exposure to conductive gains and losses.

  7. 49 CFR 218.105 - Additional operational requirements for hand-operated main track switches.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...-operated main track switches. 218.105 Section 218.105 Transportation Other Regulations Relating to... PRACTICES Handling Equipment, Switches, and Fixed Derails § 218.105 Additional operational requirements for hand-operated main track switches. (a) Each railroad shall adopt and comply with an operating...

  8. Latching relay switch assembly

    DOEpatents

    Duimstra, Frederick A.

    1991-01-01

    A latching relay switch assembly which includes a coil section and a switch or contact section. The coil section includes at least one permanent magnet and at least one electromagnet. The respective sections are, generally, arranged in separate locations or cavities in the assembly. The switch is latched by a permanent magnet assembly and selectively switched by an overriding electromagnetic assembly.

  9. Switching portfolios.

    PubMed

    Singer, Y

    1997-08-01

    A constant rebalanced portfolio is an asset allocation algorithm which keeps the same distribution of wealth among a set of assets along a period of time. Recently, there has been work on on-line portfolio selection algorithms which are competitive with the best constant rebalanced portfolio determined in hindsight (Cover, 1991; Helmbold et al., 1996; Cover and Ordentlich, 1996). By their nature, these algorithms employ the assumption that high returns can be achieved using a fixed asset allocation strategy. However, stock markets are far from being stationary and in many cases the wealth achieved by a constant rebalanced portfolio is much smaller than the wealth achieved by an ad hoc investment strategy that adapts to changes in the market. In this paper we present an efficient portfolio selection algorithm that is able to track a changing market. We also describe a simple extension of the algorithm for the case of a general transaction cost, including the transactions cost models recently investigated in (Blum and Kalai, 1997). We provide a simple analysis of the competitiveness of the algorithm and check its performance on real stock data from the New York Stock Exchange accumulated during a 22-year period. On this data, our algorithm outperforms all the algorithms referenced above, with and without transaction costs.

  10. Radiation hard vacuum switch

    DOEpatents

    Boettcher, Gordon E.

    1990-03-06

    A vacuum switch with an isolated trigger probe which is not directly connected to the switching electrodes. The vacuum switch within the plasmatron is triggered by plasma expansion initiated by the trigger probe which travels through an opening to reach the vacuum switch elements. The plasma arc created is directed by the opening to the space between the anode and cathode of the vacuum switch to cause conduction.

  11. Radiation hard vacuum switch

    DOEpatents

    Boettcher, Gordon E.

    1990-01-01

    A vacuum switch with an isolated trigger probe which is not directly connected to the switching electrodes. The vacuum switch within the plasmatron is triggered by plasma expansion initiated by the trigger probe which travels through an opening to reach the vacuum switch elements. The plasma arc created is directed by the opening to the space between the anode and cathode of the vacuum switch to cause conduction.

  12. Improved Glycemic Control Achieved by Switching to Insulin Degludec in Insulin-Treated Patients with Type 2 Diabetes in a Real-World Setting: a Non-interventional, Retrospective Cohort Study.

    PubMed

    Melzer Cohen, Cheli; Thorsted, Brian Larsen; Wolden, Michael Lyng; Chodick, Gabriel; Karasik, Avraham

    2017-09-07

    Retrospective cohort study evaluating the clinical effectiveness of insulin degludec (IDeg) in insulin-treated patients with type 2 diabetes switching from other insulins to IDeg in a real-world setting. Data were drawn from the Maccabi Health Management Organization in Israel and included patients treated with IDeg between 1 September 2014 and 29 February 2016. Main inclusion criteria were age ≥18 years, diagnosis of type 2 diabetes, and treated with insulin for at least 1 year prior to IDeg initiation. HbA1c, insulin dose, body weight, and body mass index were recorded before and 90 and 180 days post-switch. Of 211 eligible patients, 57% were male, mean age ± SD 62.2 ± 12.1 years, and diabetes duration >10 years. Switching to IDeg decreased HbA1c from a mean 8.8 ± 1.5% (73.0 ± 16.4 mmol/mol) baseline by 0.58 ± 1.0% (6.3 ± 10.9 mmol/mol) (p < 0.001). Baseline HbA1c of >8.5% (69.0 mmol/mol) and daily insulin dose of ≥50 U were associated with a greater reduction in HbA1c [1.0 ± 1.1% (10.9 ± 12.0 mmol/mol) and 1.2 ± 1.1% (13.1 ± 12.0 mmol/mol), respectively] compared with the total population. At 180 days post-switch, the mean daily basal insulin dose increased by 2 U compared with pre-switch. There was no significant change in body weight post-switch. In a real-world setting, switching from another insulin to IDeg significantly improved glycemic control in patients with type 2 diabetes, without significant weight gain and with only a modest increase in insulin dose after IDeg initiation. Novo Nordisk.

  13. Classification system adopted for fixed cutter bits

    SciTech Connect

    Winters, W.J.; Doiron, H.H.

    1988-01-01

    The drilling industry has begun adopting the 1987 International Association of Drilling Contractors' (IADC) method for classifying fixed cutter drill bits. By studying the classification codes on bit records and properly applying the new IADC fixed cutter dull grading system to recently run bits, the end-user should be able to improve the selection and usage of fixed cutter bits. Several users are developing databases for fixed cutter bits in an effort to relate field performance to some of the more prominent bit design characteristics.

  14. Technology Insertion (TI)/Industrial Process Improvement (IPI) Task Order Number 1. Quick Fix Plan for WR-ALC, 7 RCC’s

    DTIC Science & Technology

    1989-09-25

    Pumps of the Mass Spectrometers in MANPGA Aimed at improving throughput of gyro leak checking operations by modifying the exhaust venting and...personnel working within the RCC. * Vent the Vacuum Pumps of the Mass Spectrometers in MANPGA SAims at improving throughput of gyro leak checking...spectrometers for leak checking gyros. Improved throughput could be attained by modifying the exhaust venting of the mass spectrometers vacuum pump system

  15. Temporal switching jitter in photoconductive switches

    SciTech Connect

    GAUDET,JOHN A.; SKIPPER,MICHAEL C.; ABDALLA,MICHAEL D.; AHERN,SEAN M.; MAR,ALAN; LOUBRIEL,GUILLERMO M.; ZUTAVERN,FRED J.; O'MALLEY,MARTIN W.; HELGESON,WESLEY D.; ROMERO,SAMUEL P.

    2000-04-13

    This paper reports on a recent comparison made between the Air Force Research Laboratory (AFRL) gallium arsenide, optically-triggered switch test configuration and the Sandia National Laboratories (SNL) gallium arsenide, optically-triggered switch test configuration. The purpose of these measurements was to compare the temporal switch jitter times. It is found that the optical trigger laser characteristics are dominant in determining the PCSS jitter.

  16. MEMS switches having non-metallic crossbeams

    NASA Technical Reports Server (NTRS)

    Scardelletti, Maximillian C (Inventor)

    2009-01-01

    A RF MEMS switch comprising a crossbeam of SiC, supported by at least one leg above a substrate and above a plurality of transmission lines forming a CPW. Bias is provided by at least one layer of metal disposed on a top surface of the SiC crossbeam, such as a layer of chromium followed by a layer of gold, and extending beyond the switch to a biasing pad on the substrate. The switch utilizes stress and conductivity-controlled non-metallic thin cantilevers or bridges, thereby improving the RF characteristics and operational reliability of the switch. The switch can be fabricated with conventional silicon integrated circuit (IC) processing techniques. The design of the switch is very versatile and can be implemented in many transmission line mediums.

  17. Switching from high-fat to low-fat diet normalizes glucose metabolism and improves glucose-stimulated insulin secretion and insulin sensitivity but not body weight in C57BL/6J mice.

    PubMed

    Agardh, Carl-David; Ahrén, Bo

    2012-03-01

    Environmental factors such as a high-fat diet contribute to type 2 diabetes and obesity. This study examined glycemia, insulin sensitivity, and β-cell function after switching from a high-fat diet to a low-fat diet in mice. C57BL/6J mice were fed a high-fat diet or low-fat diet for 18 months, after which mice on the high-fat diet either maintained this diet or switched to a low-fat diet for 4 weeks. Body weight and glucose and insulin responses to intraperitoneal glucose were determined. Insulin secretion (insulinogenic index: the 10-minute insulin response divided by the 10-minute glucose level) and insulin sensitivity (1 divided by basal insulin) were determined. After 18 months on a high-fat diet, mice had glucose intolerance, marked hyperinsulinemia, and increased body weight compared to mice on a low-fat diet (P < 0.001). Switching from a high-fat diet to low-fat diet normalized glucose tolerance, reduced but not normalized body weight (P < 0.001), increased insulin secretion (248 ± 39 vs 141 ± 46 pmol/mmol; P = 0.028) and improved but not normalized insulin sensitivity (3.2 ± 0.1 vs 1.0 ± 0.1 [pmol/L]; P = 0.012). Switching from a high-fat diet to low-fat diet normalizes glucose tolerance and improves but not normalizes insulin secretion and insulin sensitivity. These effects are more pronounced than the reduced body weight.

  18. Improved PCR amplification for molecular analysis using DNA from long-term preserved formalin-fixed, paraffin-embedded lung cancer tissue specimens.

    PubMed

    Taga, Masataka; Eguchi, Hidetaka; Shinohara, Tomoko; Takahashi, Keiko; Ito, Reiko; Yasui, Wataru; Nakachi, Kei; Kusunoki, Yoichiro; Hamatani, Kiyohiro

    2013-01-01

    Archival tissue specimens are valuable resources of materials for molecular biological analyses in retrospective studies, especially for rare diseases or those associated with exposure to uncommon environmental events. Although successful amplification with PCR is essential for analysis of DNA extracted from archival formalin-fixed, paraffin-embedded (FFPE) tissue specimens, we have often encountered problems with poor PCR amplification of target fragments. To overcome this, we examined whether heat treatment in alkaline solution could efficiently restore the PCR template activity of DNA that had already been extracted from FFPE lung cancer tissue specimens. The effect of the heat treatment was assessed by PCR for the TP53 gene and other lung cancer-related gene loci. The heat treatment of DNA samples in borate buffer resulted in successful PCR amplification of DNA fragments ranging from 91 to 152 bp. This technique for restoration of template activity of DNA for PCR amplification is very simple and economical, and requires no special apparatus, so it may be applicable for molecular analysis of DNA samples from FFPE tissue specimens at various laboratories.

  19. Improved computational model (AQUIFAS) for activated sludge, integrated fixed-film activated sludge, and moving-bed biofilm reactor systems, part II: multilayer biofilm diffusional model.

    PubMed

    Sen, Dipankar; Randall, Clifford W

    2008-07-01

    Research was undertaken to develop a diffusional model of the biofilm that can be applied in lieu of a semi-empirical model to upgrade an activated sludge system to an integrated fixed-film activated sludge (IFAS) or moving-bed biofilm reactor (MBBR) system. The model has been developed to operate with up to 12 cells (reactors) in series, with biofilm media incorporated to one or more of the zone cells, except the anaerobic zone cells. The values of the kinetic parameters for the model were measured using pilot-scale activated sludge, IFAS, and MBBR systems. The biofilm is divided into 12 layers and has a stagnant liquid layer. Diffusion and substrate utilization are calculated for each layer. The equations are solved simultaneously using a finite difference technique. The biofilm flux model is then linked to the activated sludge model. Advanced features include the ability to compute the biofilm thickness and the effect of biofilm thickness on performance. The biofilm diffusional model is also used to provide information and create a table of biofilm yields at different substrate concentrations that can be used in the semi-empirical model.

  20. Composite Thermal Switch

    NASA Technical Reports Server (NTRS)

    McDonald, Robert; Brawn, Shelly; Harrison, Katherine; O'Toole, Shannon; Moeller, Michael

    2011-01-01

    Lithium primary and lithium ion secondary batteries provide high specific energy and energy density. The use of these batteries also helps to reduce launch weight. Both primary and secondary cells can be packaged as high-rate cells, which can present a threat to crew and equipment in the event of external or internal short circuits. Overheating of the cell interior from high current flows induced by short circuits can result in exothermic reactions in lithium primary cells and fully charged lithium ion secondary cells. Venting of the cell case, ejection of cell components, and fire have been reported in both types of cells, resulting from abuse, cell imperfections, or faulty electronic control design. A switch has been developed that consists of a thin layer of composite material made from nanoscale particles of nickel and Teflon that conducts electrons at room temperature and switches to an insulator at an elevated temperature, thus interrupting current flow to prevent thermal runaway caused by internal short circuits. The material is placed within the cell, as a thin layer incorporated within the anode and/or the cathode, to control excess currents from metal-to-metal or metal-to-carbon shorts that might result from cell crush or a manufacturing defect. The safety of high-rate cells is thus improved, preventing serious injury to personnel and sensitive equipment located near the battery. The use of recently available nanoscale particles of nickel and Teflon permits an improved, homogeneous material with the potential to be fine-tuned to a unique switch temperature, sufficiently below the onset of a catastrophic chemical reaction. The smaller particles also permit the formation of a thinner control film layer (<50 m), which can be incorporated into commercial high-rate lithium primary and secondary cells. The innovation permits incorporation in current lithium and lithium-ion cell designs with a minimal impact on cell weight and volume. The composite thermal

  1. Improved computational model (AQUIFAS) for activated sludge, integrated fixed-film activated sludge, and moving-bed biofilm reactor systems, Part I: Semi-empirical model development.

    PubMed

    Sen, Dipankar; Randall, Clifford W

    2008-05-01

    Research was undertaken to develop a model for activated sludge, integrated fixed-film activated sludge (IFAS), and moving-bed biofilm reactor (MBBR) systems. The model can operate with up to 12 cells (reactors) in series, with biofilm media incorporated to one or more cells, except the anaerobic cells. The process configuration can be any combination of anaerobic, anoxic, aerobic, post-anoxic with or without supplemental carbon, and reaeration; it can also include any combination of step feed and recycles, including recycles for mixed liquor, return activated sludge, nitrates, and membrane bioreactors. This paper presents the structure of the model. The model embeds a biofilm model into a multicell activated sludge model. The biofilm flux rates for organics, nutrients, and biomass can be computed by two methods--a semi-empirical model of the biofilm that is relatively simpler, or a diffusional model that is computationally intensive. The values of the kinetic parameters for the model were measured using pilot-scale activated sludge, IFAS, and MBBR systems. For the semiempirical version, a series of Monod equations were developed for chemical oxygen demand, ammonium-nitrogen, and oxidized-nitrogen fluxes to the biofilm. Within the equations, a second Monod expression is used to simulate the effect of changes in biofilm thickness and fraction nitrifiers in the biofilm. The biofilm flux model is then linked to the activated sludge model. The diffusional model and the verification of the models are presented in subsequent papers (Sen and Randall, 2008a, 2008b). The model can be used to quantify the amount of media and surface area required to achieve nitrification, identify the best locations for the media, and optimize the dissolved oxygen levels and nitrate recycle rates. Some of the advanced features include the ability to apply different media types and fill fractions in cells; quantify nitrification, denitrification, and biomass production in the biofilm and

  2. Improved computational model (AQUIFAS) for activated sludge, integrated fixed-film activated sludge, and moving-bed biofilm reactor systems, part III: analysis and verification.

    PubMed

    Sen, Dipankar; Randall, Clifford W

    2008-07-01

    Research was undertaken to analyze and verify a model that can be applied to activated sludge, integrated fixed-film activated sludge (IFAS), and moving-bed biofilm reactor (MBBR) systems. The model embeds a biofilm model into a multicell activated sludge model. The advantage of such a model is that it eliminates the need to run separate computations for a plant being retrofitted from activated sludge to IFAS or MBBR. The biofilm flux rates for organics, nutrients, and biomass can be computed by two methods-a semi-empirical model of the biofilm that is relatively simpler, or a diffusional model of the biofilm that is computationally intensive. Biofilm support media can be incorporated to the anoxic and aerobic cells, but not the anaerobic cells. The model can be run for steady-state and dynamic simulations. The model was able to predict the changes in nitrification and denitrification at both pilot- and full-scale facilities. The semi-empirical and diffusional models of the biofilm were both used to evaluate the biofilm flux rates for media at different locations. The biofilm diffusional model was used to compute the biofilm thickness and growth, substrate concentrations, volatile suspended solids (VSS) concentration, and fraction of nitrifiers in each layer inside the biofilm. Following calibration, both models provided similar effluent results for reactor mixed liquor VSS and mixed liquor suspended solids and for the effluent organics, nitrogen forms, and phosphorus concentrations. While the semi-empirical model was quicker to run, the diffusional model provided additional information on biofilm thickness, quantity of growth in the biofilm, and substrate profiles inside the biofilm.

  3. Adaptive optical label packet switching

    NASA Astrophysics Data System (ADS)

    Xiao, Shilin; Liu, Zhixin; Liang, Zheng; Zhao, Zhihui; Qu, Kefeng

    2007-11-01

    This paper introduces a kind of Adaptive Optical Label Packet Switching (AOLPS) technology. Based on Optical Packet Switching (OPS), AOLPS uses optical label to achieve self-routing, and the size of optical packet is self-adaptive. At the edge nodes, IP packets are fist classified into different first-in-fist-out memories (FIFOs) according to their priority levels and destinations, and then being encapsulated into optical packets. The traffic at each FIFO is real-time monitored, and the controller in edge node employs an optimal strategy to generate suitable sized packets for transmission. Large sized packets will be adopted when traffic is heavy, and small sized packets will be used when traffic is light. This self-adaptive switching granularity can greatly improve the network performance.

  4. 49 CFR 218.109 - Hand-operated fixed derails.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Hand-operated fixed derails. 218.109 Section 218.109 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD OPERATING PRACTICES Handling Equipment, Switches, and...

  5. 49 CFR 218.109 - Hand-operated fixed derails.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Hand-operated fixed derails. 218.109 Section 218.109 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD OPERATING PRACTICES Handling Equipment, Switches, and...

  6. Heat Switches for ADRs

    NASA Technical Reports Server (NTRS)

    DiPirro, M. J.; Shirron, P. J.

    2014-01-01

    Heat switches are key elements in the cyclic operation of Adiabatic Demagnetization Refrigerators (ADRs). Several of the types of heat switches that have been used for ADRs are described in this paper. Key elements in selection and design of these switches include not only ON/OFF switching ratio, but also method of actuation, size, weight, and structural soundness. Some of the trade-off are detailed in this paper.

  7. Heat switches for ADRs

    NASA Astrophysics Data System (ADS)

    DiPirro, M. J.; Shirron, P. J.

    2014-07-01

    Heat switches are key elements in the cyclic operation of Adiabatic Demagnetization Refrigerators (ADRs). Several of the types of heat switches that have been used for ADRs are described in this paper. Key elements in selection and design of these switches include not only ON/OFF switching ratio, but also method of actuation, size, weight, and structural soundness. Some of the trade-off are detailed in this paper.

  8. Remote switch actuator

    DOEpatents

    Haas, Edwin Gerard; Beauman, Ronald; Palo, Jr., Stefan

    2013-01-29

    The invention provides a device and method for actuating electrical switches remotely. The device is removably attached to the switch and is actuated through the transfer of a user's force. The user is able to remain physically removed from the switch site obviating need for protective equipment. The device and method allow rapid, safe actuation of high-voltage or high-current carrying electrical switches or circuit breakers.

  9. Disruption of the Glycine Cleavage System Enables Sinorhizobium Fredii USDA257 to Form Nitrogen-fixing Nodules on Agonomically Improved North American Soybean Cultivars

    USDA-ARS?s Scientific Manuscript database

    The symbiosis between Sinorhizobium fredii USDA257 and soybean [Glycine max (L.) Merr.] exhibits a high degree of cultivar specificity. USDA257 nodulates primitive soybean cultivars but fails to nodulate agronomically improved cultivars such as McCall. In this study we provide evidence for the invol...

  10. Apollo Ring Optical Switch

    SciTech Connect

    Maestas, J.H.

    1987-03-01

    An optical switch was designed, built, and installed at Sandia National Laboratories in Albuquerque, New Mexico, to facilitate the integration of two Apollo computer networks into a single network. This report presents an overview of the optical switch as well as its layout, switch testing procedure and test data, and installation.

  11. Triggered plasma opening switch

    DOEpatents

    Mendel, Clifford W.

    1988-01-01

    A triggerable opening switch for a very high voltage and current pulse includes a transmission line extending from a source to a load and having an intermediate switch section including a plasma for conducting electrons between transmission line conductors and a magnetic field for breaking the plasma conduction path and magnetically insulating the electrons when it is desired to open the switch.

  12. Optical Plasmonic Switch based on Graphene

    NASA Astrophysics Data System (ADS)

    Moon, Kyungsun; Park, Suk-Young

    2015-03-01

    We have studied an electro-optical plasmonic waveguide, which controls the transmission of incident light by switching the coupling of the surface plasmon polariton (SPP) localized on graphene. It has been previously shown that the propagation length of the SPP localized on the copper surface can be effectively reduced by a factor of two or three by applying external bias potential. In our study, we have demonstrated that the propagation length of the SPP localized on graphene can be dramatically reduced by a factor of ten or so and the wavelength of SPP can be reduced by several hundredths of that of the incident light as well. We have also investigated the effect of scattering times of graphene and active Si layer on switching line shape. Switching occurs upon varying the carrier density of Si layer by ?n/nc ~1% in the vicinity of switching region. For a fixed bias voltage applied just below the critical value, signal laser beam shone into the metal nano-particles may increase the carrier density as such, which will induce switching. This may help develop an all-optical nano-scale plasmonic switch. This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (NRF-2012R1A1A2006927).

  13. Improvement of bio-oil yield and quality in co-pyrolysis of corncobs and high density polyethylene in a fixed bed reactor at low heating rate

    NASA Astrophysics Data System (ADS)

    Supramono, D.; Lusiani, S.

    2016-11-01

    Over the past few decades, interest in developing biomass-derived fuel has been increasing rapidly due to the decrease in fossil fuel reserves. Bio-oil produced by biomass pyrolysis however contains high oxygen compounds resulting in low calorific-value fuel and therefore requiring upgrading. In co-pyrolysis of the feed blend of plastics of High Density Polyethylene (HDPE) and biomass of com cob particles, at some compositions free radicals from plastic decomposition containing more hydrogen radicals are able to bond oxygen radicals originating from biomass to reduce oxygenate compounds in the bio-oil thus increasing bio-oil quality. This phenomenon is usually called synergetic effect. In addition to that, the pattern of heating of the feed blend in the pyrolysis reactor is predicted to affect biooil quality and yield. In a batch reactor, co-pyrolysis of corncobs and HDPE requires low heating rate to reach a peak temperature at temperature rise period followed by heating for some time at peak temperature called holding time at constant temperature period. No research has been carried out to investigate how long holding time is set in co-pyrolysis of plastic and biomass to obtain high yield of bio-oil. Holding time may affect either crosslinking of free radicals in gas phase, which increases char product, or secondary pyrolysis in the gas phase, which increases non-condensable gas in the gas phase of pyrolysis reactor, both of which reduce bio-oil yield. Therefore, holding time of co-pyrolysis affects the mass rate of bio-oil formation as the pyrolysis proceeds and quality of the bio-oil. In the present work, effects of holding time on the yield and quality of bio-oil have been investigated using horizontal fixed bed of the feed blends at heating rate of 5°C, peak temperature of 500°C and N2 flow rate of 700 ml/minute. Holding time was varied from 0 to 70 minutes with 10 minutes interval. To investigate the effects of holding time, the composition of HDPE in the

  14. REMOTE CONTROLLED SWITCHING DEVICE

    DOEpatents

    Hobbs, J.C.

    1959-02-01

    An electrical switching device which can be remotely controlled and in which one or more switches may be accurately operated at predetermined times or with predetermined intervening time intervals is described. The switching device consists essentially of a deck, a post projecting from the deck at right angles thereto, cam means mounted for rotation around said posts and a switch connected to said deck and actuated by said cam means. Means is provided for rotating the cam means at a constant speed and the switching apparatus is enclosed in a sealed container with external adjusting means and electrical connection elements.

  15. Wide Bandgap Extrinsic Photoconductive Switches

    NASA Astrophysics Data System (ADS)

    Sullivan, James Stephen

    Wide Bandgap Extrinsic Photoconductive Switches Semi-insulating Gallium Nitride, 4H and 6H Silicon Carbide are attractive materials for compact, high voltage, extrinsic, photoconductive switches due to their wide bandgap, high dark resistance, high critical electric field strength and high electron saturation velocity. These wide bandgap semiconductors are made semi-insulating by the addition of vanadium (4H and 6H-SiC) and iron (2H-GaN) impurities that form deep acceptors. These deep acceptors trap electrons donated from shallow donor impurities. The electrons can be optically excited from these deep acceptor levels into the conduction band to transition the wide bandgap semiconductor materials from a semi-insulating to a conducting state. Extrinsic photoconductive switches with opposing electrodes have been constructed using vanadium compensated 6H-SiC and iron compensated 2H-GaN. These extrinsic photoconductive switches were tested at high voltage and high power to determine if they could be successfully used as the closing switch in compact medical accelerators. The successful development of a vanadium compensated, 6H-SiC extrinsic photoconductive switch for use as a closing switch for compact accelerator applications was realized by improvements made to the vanadium, nitrogen and boron impurity densities. The changes made to the impurity densities were based on the physical intuition outlined and simple rate equation models. The final 6H-SiC impurity 'recipe' calls for vanadium, nitrogen and boron densities of 2.5 e17 cm-3, 1.25e17 cm-3 and ≤ 1e16 cm-3, respectively. This recipe was originally developed to maximize the quantum efficiency of the vanadium compensated 6H-SiC, while maintaining a thermally stable semi-insulating material. The rate equation models indicate that, besides increasing the quantum efficiency, the impurity recipe should be expected to also increase the carrier recombination time. Three generations of 6H-SiC materials were tested. The

  16. On the Switching Control

    NASA Astrophysics Data System (ADS)

    Balas, Valentina E.; Balas, Marius M.

    2009-04-01

    The paper is discussing the measures able to reject the instability that may unexpectedly appear in particular conditions, in switching controllers applications. The switching controllers' effect is explained by the combined effects of the unsuitable choice of the switching moments (in the first or third quadrants of the phase trajectory of the switching error) and of the temporal aliasing that can distort the digital control systems when the sampling rate is close to the frequency of the oscillations that are produced by the commutation. The correct switching moments are located into the second and fourth quadrants of the phase trajectory of the switching error, but an active preparation of the commutation may be simply achieved by using a tracking controller, that is driving the output of open loop controller to follow the output of the close loop controller, permanently minimizing the switching error. Simulations issued from a dc driver speed controller and from an aircraft are provided.

  17. Improved IgG3 levels and reduced infection rate in a woman with CVID switched from intravenous to subcutaneous immunoglobulin therapy.

    PubMed

    Shapiro, Ralph S

    2012-12-01

    To report the interesting case of a patient with common variable immune deficiency disease who demonstrated varied responses to intravenous (IV) and subcutaneous (SC) immunoglobulin (Ig) therapy with regard to both infection frequencies and IgG3 subclass determinations. As part of routine medical care, the author monitored total and IgG subclass levels, along with infection frequencies in a 35-year-old woman, with recurrent sinopulmonary infections diagnosed with common variable immune deficiency disease. During treatment with IVIg, the patient's annual rate of infections decreased, although she experienced severe headaches. After being switched to daily SCIg therapy, the headaches stopped, and her annual infection rate declined further. Her IgG3 levels, which were undetectable during IVIg therapy, increased substantially during SCIg treatment. The reason for the observed correlation between IgG3 level restoration and a decline in infection rate after being switched to SCIg therapy is not entirely clear. At the minimum, it may suggest that IgG3 levels may be a simple and useful surrogate marker to monitor Ig replacement sufficiency in certain patients.

  18. Shuttle-promoted nano-mechanical current switch

    SciTech Connect

    Song, Taegeun Kiselev, Mikhail N.; Gorelik, Leonid Y.; Shekhter, Robert I.; Kikoin, Konstantin

    2015-09-21

    We investigate electron shuttling in three-terminal nanoelectromechanical device built on a movable metallic rod oscillating between two drains. The device shows a double-well shaped electromechanical potential tunable by a source-drain bias voltage. Four stationary regimes controllable by the bias are found for this device: (i) single stable fixed point, (ii) two stable fixed points, (iii) two limit cycles, and (iv) single limit cycle. In the presence of perpendicular magnetic field, the Lorentz force makes possible switching from one electromechanical state to another. The mechanism of tunable transitions between various stable regimes based on the interplay between voltage controlled electromechanical instability and magnetically controlled switching is suggested. The switching phenomenon is implemented for achieving both a reliable active current switch and sensoring of small variations of magnetic field.

  19. Switching from premixed insulin to glargine-based insulin regimen improves glycaemic control in patients with type 1 or type 2 diabetes: a retrospective primary care-based analysis

    PubMed Central

    Sharplin, Peter; Gordon, Jason; Peters, John R; Tetlow, Anthony P; Longman, Andrea J; McEwan, Philip

    2009-01-01

    Background Insulin glargine (glargine) and premixed insulins (premix) are alternative insulin treatments. This analysis evaluated glycaemic control in 528 patients with type 1 (n = 183) or type 2 (n = 345) diabetes, after switching from premix to a glargine-based regimen, using unselected general practice (GP) data. Methods Data for this retrospective observational analysis were extracted from a UK GP database (The Health Improvement Network). Patients were required to have at least 12 months of available data, before and after, switching from premix to a glargine-based regimen. The principal analysis was the change in HbA1c after 12 months of treatment with glargine; secondary analyses included change in weight, bolus usage and total daily insulin dose. Inconsistent reporting of hypoglycemic episodes precludes reliable assessment of this outcome. Multivariate analyses were used to adjust for baseline characteristics and confounding variables. Results Both cohorts showed significant reduction in mean HbA1c 12 months after the switch: by -0.67% (p < 0.001) in the type 1 cohort and by -0.53% (p < 0.001) in the type 2 cohort (adjusted data). The size of HbA1c improvement was positively correlated with baseline HbA1c; patients with a baseline HbA1c ≥ 10% had the greatest mean reduction in HbA1c, by -1.7% (p < 0.001) and -1.2% (p < 0.001), respectively. The proportion of patients receiving co-bolus prescriptions increased in the type 1 (mean 24.6% to 95.1%, p < 0.001) and type 2 (mean 16.2% to 73.9%, p < 0.001) cohorts. There was no significant change in weight in either cohort. Total mean insulin use increased in type 2 diabetes patients (from 0.67 ± 1.35 U/Kg to 0.88 ± 1.33 U/Kg, p < 0.001) with a slight decrease in type 1 diabetes patients (from 1.04 ± 2.51 U/Kg to 0.98 ± 2.58 U/Kg, p < 0.001). Conclusion In everyday practice, patients with type 1 or type 2 diabetes inadequately controlled by premix insulins experienced significant improvement in glycaemic

  20. Up-down hand position switch may delay the fatigue of non-dominant hand position rescuers and improve chest compression quality during cardiopulmonary resuscitation: a randomized crossover manikin study.

    PubMed

    Zhou, Xian-Long; Li, Lei; Jiang, Cheng; Xu, Bing; Wang, Huang-Lei; Xiong, Dan; Sheng, Li-Pin; Yang, Qi-Sheng; Jiang, Shan; Xu, Peng; Chen, Zhi-Qiao; Zhao, Yan

    2015-01-01

    Previous studies have shown improved external chest compression (ECC) quality and delayed rescuer fatigue when the dominant hand (DH) was in contact with the sternum. However, many rescuers prefer placing the non-dominant hand (NH) in contact with the sternum during ECC. We aimed to investigate the effects of up-down hand position switch on the quality of ECC and the fatigue of rescuers during cardiopulmonary resuscitation (CPR). After completion of a review of the standard adult basic life support (BLS) course, every candidate performed 10 cycles of single adult CPR twice on an adult manikin with either a constant hand position (CH) or a switched hand position (SH) in random order at 7-day intervals. The rescuers' general characteristics, hand positions, physiological signs, fatigue appearance and ECC qualities were recorded. Our results showed no significant differences in chest compression quality for the DH position rescuers between the CH and SH sessions (p>0.05, resp.). And also no significant differences were found for Borg score (p = 0.437) or cycle number (p = 0.127) of fatigue appearance after chest compressions between the two sessions. However, for NH position rescuers, the appearance of fatigue was delayed (p = 0.046), with a lower Borg score in the SH session (12.67 ± 2.03) compared to the CH session (13.33 ± 1.95) (p = 0.011). Moreover, the compression depth was significantly greater in the SH session (39.3 ± 7.2 mm) compared to the CH session (36.3 ± 8.1 mm) (p = 0.015). Our data suggest that the up-down hand position switch during CPR may delay the fatigue of non-dominant hand position rescuers and improve the quality of chest compressions.

  1. Up-Down Hand Position Switch May Delay the Fatigue of Non-Dominant Hand Position Rescuers and Improve Chest Compression Quality during Cardiopulmonary Resuscitation: A Randomized Crossover Manikin Study

    PubMed Central

    Xu, Bing; Wang, Huang-Lei; Xiong, Dan; Sheng, Li-Pin; Yang, Qi-Sheng; Jiang, Shan; Xu, Peng; Chen, Zhi-Qiao; Zhao, Yan

    2015-01-01

    Previous studies have shown improved external chest compression (ECC) quality and delayed rescuer fatigue when the dominant hand (DH) was in contact with the sternum. However, many rescuers prefer placing the non-dominant hand (NH) in contact with the sternum during ECC. We aimed to investigate the effects of up-down hand position switch on the quality of ECC and the fatigue of rescuers during cardiopulmonary resuscitation (CPR). After completion of a review of the standard adult basic life support (BLS) course, every candidate performed 10 cycles of single adult CPR twice on an adult manikin with either a constant hand position (CH) or a switched hand position (SH) in random order at 7-day intervals. The rescuers’ general characteristics, hand positions, physiological signs, fatigue appearance and ECC qualities were recorded. Our results showed no significant differences in chest compression quality for the DH position rescuers between the CH and SH sessions (p>0.05, resp.). And also no significant differences were found for Borg score (p = 0.437) or cycle number (p = 0.127) of fatigue appearance after chest compressions between the two sessions. However, for NH position rescuers, the appearance of fatigue was delayed (p = 0.046), with a lower Borg score in the SH session (12.67 ± 2.03) compared to the CH session (13.33 ± 1.95) (p = 0.011). Moreover, the compression depth was significantly greater in the SH session (39.3 ± 7.2 mm) compared to the CH session (36.3 ± 8.1 mm) (p = 0.015). Our data suggest that the up-down hand position switch during CPR may delay the fatigue of non-dominant hand position rescuers and improve the quality of chest compressions. PMID:26267353

  2. Subpicosecond photonic switching based on bacteriorhodopsin

    NASA Astrophysics Data System (ADS)

    Ormos, Pal; Fabian, Laszlo; Heiner, Zsuzsanna; Mero, Mark; Kiss, Miklos; Wolff, Elmar; Osvay, Karoly; der, Andras

    2011-03-01

    All-optical data processing is the most promising approach for further improvement in data trafficking. We present a subpicosecond photonic switch where the active role is performed by the chromoprotein bacteriorhodopsin. The changes in the refractive index that accompany the steps of the photocycle of bacteriorhodopsin are used for all optical switching in appropriate integrated optical devices. We use grating coupled planar waveguides and the coupling is modulated by the light induced refractive index changes of bacteriorhodopsin. The switching is demonstrated in ultrafast pump-probe experiments. Different transitions of the photocycle are explored for switching applications. We show that by using the bR to I transition subpicosecond switching can be readily achieved. The approach is a basis for protein-based integrated optical devices, eventually leading to a conceptual revolution in telecommunications technologies.

  3. X-ray crystal structures of Escherichia coli RNA polymerase with switch region binding inhibitors enable rational design of squaramides with an improved fraction unbound to human plasma protein

    PubMed Central

    Molodtsov, Vadim; Fleming, Paul R.; Eyermann, Charles J.; Ferguson, Andrew D.; Foulk, Melinda A.; McKinney, David C.; Masse, Craig E.; Buurman, Ed T.; Murakami, Katsuhiko S.

    2015-01-01

    Squaramides constitute a novel class of RNA polymerase inhibitors of which genetic evidence and computational modeling previously have suggested an inhibitory mechanism mediated by binding to the RNA polymerase switch region. An iterative chemistry program increased the fraction unbound to human plasma protein from below minimum detection levels, i.e. <1%, to 4~6%, while retaining biochemical potency. Since in vitro antimicrobial activity against an efflux-negative strain of Haemophilus influenzae was 4~8-fold higher, the combined improvement was at least 20~60-fold. Co-crystal structures of Escherichia coli RNA polymerase with two key squaramides showed displacement of the switch 2, predicted to interfere with the conformational change of clamp domain and/or with binding of non-template DNA, a mechanism akin to that of natural product myxopyronin. Furthermore, the structures confirmed the chemical features required for biochemical potency. The terminal isoxazole and benzyl rings bind into distinct relatively narrow, hydrophobic pockets and both are required for biochemical potency. In contrast, the linker composed of squarate and piperidine accesses different conformations in their respective co-crystal structures with RNA polymerase, reflecting its main role of proper orientation of the aforementioned terminal rings. These observations further explain the tolerance of hydrophilic substitutions in the linker region that was exploited to improve the fraction unbound to human plasma protein while retaining biochemical potency. PMID:25798859

  4. Improving growth rate of microalgae in a 1191m(2) raceway pond to fix CO2 from flue gas in a coal-fired power plant.

    PubMed

    Cheng, Jun; Yang, Zongbo; Huang, Yun; Huang, Lei; Hu, Lizuo; Xu, Donghua; Zhou, Junhu; Cen, Kefa

    2015-08-01

    CO2 fixation between microalgal biomass and culture solution and the weight ratio of biomass consumption at nighttime to biomass growth at daytime were compared in an open raceway pond aerated with flue gas from a coal-fired power plant. Average daytime sunlight intensity and solution temperature were optimized to improve microalgal growth rate and to enhance the efficiency of CO2 fixation. When the average daytime solution temperature increased from 12 to 26°C, the rate of biomass consumption due to microalgal respiration at nighttime increased from 6.0 to 7.9g/m(2)/d, which was approximately 25% of the biomass growth rate at daytime. Furthermore, when the average daytime sunlight intensity increased from 39,900 to 88,300lux, CO2 fixation rate in the microalgal biomass increased from 18.4 to 40.7g/m(2)/d, which was approximately 1/3 of CO2 removal rate from flue gas by the microalgal culture system.

  5. Optoelectronic techniques for broadband switching

    NASA Astrophysics Data System (ADS)

    Su, S. F.; Jou, L.; Lenart, J.

    1988-01-01

    Optoelectronic switching employs a hybrid optical/electronic principle to perform the switching function and is applicable for either analog broadband or high-bit rate digital switching. The major advantages of optoelectronic switching include high isolation, low crosstalk, small physical size, light weight, and low power consumption. These advantages make optoelectronic switching an excellent candidate for on-board satellite switching. This paper describes a number of optoelectronic switching architectures. System components required for implementing these switching architectures are discussed. Performance of these architectures are evaluated by calculating their crosstalk, isolation, insertion loss, matrix size, drive power, throughput, and switching speed. Technologies needed for monolithic optoelectronic switching are also identified.

  6. Surface flashover threshold and switched fields of photoconductive semiconductor switches

    SciTech Connect

    Loubriel, G.M.; O'Malley, M.W.; Zutavern, F.J.; McKenzie, B.B.; Conley, W.R.

    1988-01-01

    We have shown that Si Photoconductive Semiconductor Switches (PCSS) can be used to switch high voltages (up to 123 kV), high fields (up to 82 kV/cm) and high currents (2.8 kA). The ability of the samples to withstand this type of high voltage, high current switching depends on the way in which the current penetrates the semiconductor. The appropriate use of water or contacts greatly improves the switching capability. We have also shown that the wafers can support large currents (4.0 kA for GaAs and 2.8 kA for Si) and large linear current densities (3.2 kA/cm for GaAs and 1.4 kA/cm for Si). For GaAs this linear current density corresponds to about 1 Ma/cm/sup 2/ given a penetration depth of about 10/sup /minus/3/ cm. 4 refs., 4 figs., 2 tabs.

  7. How to improve fertility of African soils? Leguminous fallows (Cameroon), addition of farmyard manure and mineral fertilizer (Kenya), organic residues management and introduction of N2 fixing species in forest plantations (Congo).

    NASA Astrophysics Data System (ADS)

    Koutika, Lydie-Stella; Mareschal, Louis; Mouanda, Cadeau; Epron, Daniel

    2014-05-01

    Most of African soils are inherently infertile and poor in nutrients mainly nitrogen and phosphorus. Several practices are used to improve soil fertility, increase productivity and ensure their sustainability. Soil fertility in the leguminous fallows was evaluated through particulate organic matter (POM), the more active part of soil organic matter (SOM) in Cameroon. The combination of mineral and organic (manure) fertilizers increased microbial P biomass allowing the release of P along the plant growing period in the Kenyan soils. Organic residues management and introduction of nitrogen fixing species (Acacia) were used to improve soil fertility and sustain forest productivity on the coastal plains of Congo. SOM fractionation was made under Pueraria, Mucuna fallows and natural regrowth mainly Chromolaena and under 3 forest plantation treatments installed in previous savanna: 1) no input, 2) normal input, and 3) double input of organic residues. Microbial P biomass and sequential P fractionation were evaluated in high and low P fixing soils. N, C, available P and pH were determined on soil sampled in acacia (100A), eucalypt (100E) and mixed-species (50A:50E) stands. N and P were determined in aboveground litters and in leaves, bark and wood of trees. The two leguminous fallows increased N content in POM fractions i.e., N >1% for Pueraria and Mucuna against N<1% for natural regrowth in the 0-0.10m depth, probably through N input from N2 fixation from the atmosphere (Cameroon).The addition of mineral fertilizers and farmyard manure increases P biomass (4.8 after 2 weeks to 15.2 after 16 weeks), and then decreased to 9.7 mg P g-1 soil (week 32). It also changes the P Hedley fractions partition in the high P fixing Kenyan soil (0-0.10m). After two rotations (14 years), SOM mineralization was the highest in the double input of organic residues treatment (low coarse POM 5.6 g kg-1 of soil and high organo-mineral fraction (OMF) 115 g kg-1 of soil). The introduction of A

  8. A solid-state dielectric elastomer switch for soft logic

    SciTech Connect

    Chau, Nixon; Slipher, Geoffrey A. Mrozek, Randy A.; O'Brien, Benjamin M.; Anderson, Iain A.

    2016-03-07

    In this paper, we describe a stretchable solid-state electronic switching material that operates at high voltage potentials, as well as a switch material benchmarking technique that utilizes a modular dielectric elastomer (artificial muscle) ring oscillator. The solid-state switching material was integrated into our oscillator, which self-started after 16 s and performed 5 oscillations at a frequency of 1.05 Hz with 3.25 kV DC input. Our materials-by-design approach for the nickel filled polydimethylsiloxane based switch has resulted in significant improvements over previous carbon grease-based switches in four key areas, namely, sharpness of switching behavior upon applied stretch, magnitude of electrical resistance change, ease of manufacture, and production rate. Switch lifetime was demonstrated to be in the range of tens to hundreds of cycles with the current process. An interesting and potentially useful strain-based switching hysteresis behavior is also presented.

  9. A solid-state dielectric elastomer switch for soft logic

    NASA Astrophysics Data System (ADS)

    Chau, Nixon; Slipher, Geoffrey A.; O'Brien, Benjamin M.; Mrozek, Randy A.; Anderson, Iain A.

    2016-03-01

    In this paper, we describe a stretchable solid-state electronic switching material that operates at high voltage potentials, as well as a switch material benchmarking technique that utilizes a modular dielectric elastomer (artificial muscle) ring oscillator. The solid-state switching material was integrated into our oscillator, which self-started after 16 s and performed 5 oscillations at a frequency of 1.05 Hz with 3.25 kV DC input. Our materials-by-design approach for the nickel filled polydimethylsiloxane based switch has resulted in significant improvements over previous carbon grease-based switches in four key areas, namely, sharpness of switching behavior upon applied stretch, magnitude of electrical resistance change, ease of manufacture, and production rate. Switch lifetime was demonstrated to be in the range of tens to hundreds of cycles with the current process. An interesting and potentially useful strain-based switching hysteresis behavior is also presented.

  10. Large-scale silicon optical switches for optical interconnection

    NASA Astrophysics Data System (ADS)

    Qiao, Lei; Tang, Weijie; Chu, Tao

    2016-11-01

    Large-scale optical switches are greatly demanded in building optical interconnections in data centers and high performance computers (HPCs). Silicon optical switches have advantages of being compact and CMOS process compatible, which can be easily monolithically integrated. However, there are difficulties to construct large ports silicon optical switches. One of them is the non-uniformity of the switch units in large scale silicon optical switches, which arises from the fabrication error and causes confusion in finding the unit optimum operation points. In this paper, we proposed a method to detect the optimum operating point in large scale switch with limited build-in power monitors. We also propose methods for improving the unbalanced crosstalk of cross/bar states in silicon electro-optical MZI switches and insertion losses. Our recent progress in large scale silicon optical switches, including 64 × 64 thermal-optical and 32 × 32 electro-optical switches will be introduced. To the best our knowledge, both of them are the largest scale silicon optical switches in their sections, respectively. The switches were fabricated on 340-nm SOI substrates with CMOS 180- nm processes. The crosstalk of the 32 × 32 electro-optic switch was -19.2dB to -25.1 dB, while the value of the 64 × 64 thermal-optic switch was -30 dB to -48.3 dB.

  11. PPARγ Ligands Switched High Fat Diet-Induced Macrophage M2b Polarization toward M2a Thereby Improving Intestinal Candida Elimination

    PubMed Central

    Olagnier, David; Bernad, José; Perez, Laurence; Burcelin, Rémy; Valentin, Alexis; Auwerx, Johan; Pipy, Bernard; Coste, Agnès

    2010-01-01

    Obesity is associated with a chronic low-grade inflammation that predisposes to insulin resistance and the development of type 2 diabetes. In this metabolic context, gastrointestinal (GI) candidiasis is common. We recently demonstrated that the PPARγ ligand rosiglitazone promotes the clearance of Candida albicans through the activation of alternative M2 macrophage polarization. Here, we evaluated the impact of high fat diet (HFD)-induced obesity and the effect of rosiglitazone (PPARγ ligand) or WY14643 (PPARα ligand) both on the phenotypic M1/M2 polarization of peritoneal and cecal tissue macrophages and on the outcome of GI candidiasis. We demonstrated that the peritoneal macrophages and the cell types present in the cecal tissue from HF fed mice present a M2b polarization (TNF-αhigh, IL-10high, MR, Dectin-1). Interestingly, rosiglitazone induces a phenotypic M2b-to-M2a (TNF-αlow, IL-10low, MRhigh, Dectin-1high) switch of peritoneal macrophages and of the cells present in the cecal tissue. The incapacity of WY14643 to switch this polarization toward M2a state, strongly suggests the specific involvement of PPARγ in this mechanism. We showed that in insulin resistant mice, M2b polarization of macrophages present on the site of infection is associated with an increased susceptibility to GI candidiasis, whereas M2a polarization after rosiglitazone treatment favours the GI fungal elimination independently of reduced blood glucose. In conclusion, our data demonstrate a dual benefit of PPARγ ligands because they promote mucosal defence mechanisms against GI candidiasis through M2a macrophage polarization while regulating blood glucose level. PMID:20877467

  12. Monolithic Microwave Switching Matrix

    NASA Technical Reports Server (NTRS)

    Fujikawa, Gene; Ch'en, Daniel R.; Petersen, Wendell C.

    1989-01-01

    Gallium arsenide integrated-circuit chip switches any of three microwave input signals to any of three output ports. Measuring 4.9 mm on side, chip contains nine field-effect transistor (FET) crosspoint switches. Housed in custom-designed package with standard connectors for easy integration into system. FET's on chip operated as passive switches and consume no static power and insignificant amounts of switching power. Chip module cascades with similar modules into large arrays handling as many as 100 inputs and 100 outputs. Applications include switching and routing vast amounts of data between computers at extremely high speed. On communications satellite, chip switches microwave signals to and from Earth stations and other satellites.

  13. Effective switching frequency multiplier inverter

    DOEpatents

    Su, Gui-Jia; Peng, Fang Z.

    2007-08-07

    A switching frequency multiplier inverter for low inductance machines that uses parallel connection of switches and each switch is independently controlled according to a pulse width modulation scheme. The effective switching frequency is multiplied by the number of switches connected in parallel while each individual switch operates within its limit of switching frequency. This technique can also be used for other power converters such as DC/DC, AC/DC converters.

  14. Double-Bounce Switching

    DTIC Science & Technology

    1983-06-01

    module. Adjustments provided to investigate double- bounce switching are noted. limitation is at a higher level and occurs in the conventionally...To be presented at the 4th IEEE PUlsed Power Conference, June 6-8, 1983, Albuquerque, NM. DOUBLE- BOUNCE SWITCHING* George B. Frazier and Steven R...Ashby Physics International Company 2700 Merced Street San Leandro, California 94577 Abstract Double- bounce switching is a technique for

  15. Avalanche Photoconductive Switching

    DTIC Science & Technology

    1989-06-01

    held off across the switch. In our case this corresponds to 70 kV/cm and is limited by surface flashover . The pulse length is determined by the...off across the gap of the switch, which in turn appears to be limited by surface flashover . There appears to be a threshold electric field of 20-60...and understand this mode of operation. Introduction Laser activated photoconductive switching in semiconductors is a promising technology for high

  16. Thermally actuated thermionic switch

    DOEpatents

    Barrus, Donald M.; Shires, Charles D.

    1988-01-01

    A thermally actuated thermionic switch which responds to an increase of temperature by changing from a high impedance to a low impedance at a predictable temperature set point. The switch has a bistable operation mode switching only on temperature increases. The thermionic material may be a metal which is liquid at the desired operation temperature and held in matrix in a graphite block reservoir, and which changes state (ionizes, for example) so as to be electrically conductive at a desired temperature.

  17. Thermally actuated thermionic switch

    DOEpatents

    Barrus, D.M.; Shires, C.D.

    1982-09-30

    A thermally actuated thermionic switch which responds to an increase of temperature by changing from a high impedance to a low impedance at a predictable temperature set point. The switch has a bistable operation mode switching only on temperature increases. The thermionic material may be a metal which is liquid at the desired operation temperature and held in matrix in a graphite block reservoir, and which changes state (ionizes, for example) so as to be electrically conductive at a desired temperature.

  18. Solid state switch

    DOEpatents

    Merritt, Bernard T.; Dreifuerst, Gary R.

    1994-01-01

    A solid state switch, with reverse conducting thyristors, is designed to operate at 20 kV hold-off voltage, 1500 A peak, 1.0 .mu.s pulsewidth, and 4500 pps, to replace thyratrons. The solid state switch is more reliable, more economical, and more easily repaired. The switch includes a stack of circuit card assemblies, a magnetic assist and a trigger chassis. Each circuit card assembly contains a reverse conducting thyristor, a resistor capacitor network, and triggering circuitry.

  19. AC magnetohydrodynamic microfluidic switch

    SciTech Connect

    Lemoff, A V; Lee, A P

    2000-03-02

    A microfluidic switch has been demonstrated using an AC Magnetohydrodynamic (MHD) pumping mechanism in which the Lorentz force is used to pump an electrolytic solution. By integrating two AC MHD pumps into different arms of a Y-shaped fluidic circuit, flow can be switched between the two arms. This type of switch can be used to produce complex fluidic routing, which may have multiple applications in {micro}TAS.

  20. Future Fixed Target Facilities

    SciTech Connect

    Melnitchouk, Wolodymyr

    2009-01-01

    We review plans for future fixed target lepton- and hadron-scattering facilities, including the 12 GeV upgraded CEBAF accelerator at Jefferson Lab, neutrino beam facilities at Fermilab, and the antiproton PANDA facility at FAIR. We also briefly review recent theoretical developments which will aid in the interpretation of the data expected from these facilities.

  1. Fixing Dataset Search

    NASA Technical Reports Server (NTRS)

    Lynnes, Chris

    2014-01-01

    Three current search engines are queried for ozone data at the GES DISC. The results range from sub-optimal to counter-intuitive. We propose a method to fix dataset search by implementing a robust relevancy ranking scheme. The relevancy ranking scheme is based on several heuristics culled from more than 20 years of helping users select datasets.

  2. Fixed mount wavefront sensor

    DOEpatents

    Neal, Daniel R.

    2000-01-01

    A rigid mount and method of mounting for a wavefront sensor. A wavefront dissector, such as a lenslet array, is rigidly mounted at a fixed distance relative to an imager, such as a CCD camera, without need for a relay imaging lens therebetween.

  3. Antenna Switching Schemes for Downlink Time Switched Transmit Diversity with ARQ in Rayleigh Fading Channels

    NASA Astrophysics Data System (ADS)

    Jeon, Cha-Eul; Hwang, Seung-Hoon

    For automatic repeat request (ARQ)-aided TSTD (Time Switched Transmit Diversity) system, a receiver sends the acknowledgement signal (ACK or NACK) to a transmitter in order to predict the condition of the channel. In this paper, two antenna switching schemes, in which the NACK trigger the transmit antenna switching in the proposed antenna switching patterns, are proposed for the TSTD with the ARQ in WCDMA LCR-TDD systems. In addition, the system performances are investigated. Simulation results demonstrate that the performances of the TSTD systems can be improved by applying the ARQ scheme. Furthermore, the performances of ARQ-aided TSTD systems may be significantly improved by applying the proposed antenna switching schemes, especially when the mobile's speed is low.

  4. Reusable fast opening switch

    DOEpatents

    Van Devender, J.P.; Emin, D.

    1983-12-21

    A reusable fast opening switch for transferring energy, in the form of a high power pulse, from an electromagnetic storage device such as an inductor into a load. The switch is efficient, compact, fast and reusable. The switch comprises a ferromagnetic semiconductor which undergoes a fast transition between conductive and metallic states at a critical temperature and which undergoes the transition without a phase change in its crystal structure. A semiconductor such as europium rich europhous oxide, which undergoes a conductor to insulator transition when it is joule heated from its conductor state, can be used to form the switch.

  5. Reusable fast opening switch

    DOEpatents

    Van Devender, John P.; Emin, David

    1986-01-01

    A reusable fast opening switch for transferring energy, in the form of a high power pulse, from an electromagnetic storage device such as an inductor into a load. The switch is efficient, compact, fast and reusable. The switch comprises a ferromagnetic semiconductor which undergoes a fast transition between conductive and insulating states at a critical temperature and which undergoes the transition without a phase change in its crystal structure. A semiconductor such as europium rich europhous oxide, which undergoes a conductor to insulator transition when it is joule heated from its conductor state, can be used to form the switch.

  6. Class E/F switching power amplifiers

    NASA Technical Reports Server (NTRS)

    Hajimiri, Seyed-Ali (Inventor); Aoki, Ichiro (Inventor); Rutledge, David B. (Inventor); Kee, Scott David (Inventor)

    2004-01-01

    The present invention discloses a new family of switching amplifier classes called class E/F amplifiers. These amplifiers are generally characterized by their use of the zero-voltage-switching (ZVS) phase correction technique to eliminate of the loss normally associated with the inherent capacitance of the switching device as utilized in class-E amplifiers, together with a load network for improved voltage and current wave-shaping by presenting class-F.sup.-1 impedances at selected overtones and class-E impedances at the remaining overtones. The present invention discloses a several topologies and specific circuit implementations for achieving such performance.

  7. Reversible optical control of cyanine fluorescence in fixed and living cells: optical lock-in detection immunofluorescence imaging microscopy

    PubMed Central

    Yan, Yuling; Petchprayoon, Chutima; Mao, Shu; Marriott, Gerard

    2013-01-01

    Optical switch probes undergo rapid and reversible transitions between two distinct states, one of which may fluoresce. This class of probe is used in various super-resolution imaging techniques and in the high-contrast imaging technique of optical lock-in detection (OLID) microscopy. Here, we introduce optimized optical switches for studies in living cells under standard conditions of cell culture. In particular, a highly fluorescent cyanine probe (Cy or Cy3) is directly or indirectly linked to naphthoxazine (NISO), a highly efficient optical switch that undergoes robust, 405/532 nm-driven transitions between a colourless spiro (SP) state and a colourful merocyanine (MC) state. The intensity of Cy fluorescence in these Cy/Cy3-NISO probes is reversibly modulated between a low and high value in SP and MC states, respectively, as a result of Förster resonance energy transfer. Cy/Cy3-NISO probes are targeted to specific proteins in living cells where defined waveforms of Cy3 fluorescence are generated by optical switching of the SP and MC states. Finally, we introduce a new imaging technique (called OLID-immunofluorescence microscopy) that combines optical modulation of Cy3 fluorescence from Cy3/NISO co-labelled antibodies within fixed cells and OLID analysis to significantly improve image contrast in samples having high background or rare antigens. PMID:23267183

  8. Reversible optical control of cyanine fluorescence in fixed and living cells: optical lock-in detection immunofluorescence imaging microscopy.

    PubMed

    Yan, Yuling; Petchprayoon, Chutima; Mao, Shu; Marriott, Gerard

    2013-02-05

    Optical switch probes undergo rapid and reversible transitions between two distinct states, one of which may fluoresce. This class of probe is used in various super-resolution imaging techniques and in the high-contrast imaging technique of optical lock-in detection (OLID) microscopy. Here, we introduce optimized optical switches for studies in living cells under standard conditions of cell culture. In particular, a highly fluorescent cyanine probe (Cy or Cy3) is directly or indirectly linked to naphthoxazine (NISO), a highly efficient optical switch that undergoes robust, 405/532 nm-driven transitions between a colourless spiro (SP) state and a colourful merocyanine (MC) state. The intensity of Cy fluorescence in these Cy/Cy3-NISO probes is reversibly modulated between a low and high value in SP and MC states, respectively, as a result of Förster resonance energy transfer. Cy/Cy3-NISO probes are targeted to specific proteins in living cells where defined waveforms of Cy3 fluorescence are generated by optical switching of the SP and MC states. Finally, we introduce a new imaging technique (called OLID-immunofluorescence microscopy) that combines optical modulation of Cy3 fluorescence from Cy3/NISO co-labelled antibodies within fixed cells and OLID analysis to significantly improve image contrast in samples having high background or rare antigens.

  9. Multi-line triggering and interdigitated electrode structure for photoconductive semiconductor switches

    DOEpatents

    Mar, Alan; Zutavern, Fred J.; Loubriel, Guillermo

    2007-02-06

    An improved photoconductive semiconductor switch comprises multiple-line optical triggering of multiple, high-current parallel filaments between the switch electrodes. The switch can also have a multi-gap, interdigitated electrode for the generation of additional parallel filaments. Multi-line triggering can increase the switch lifetime at high currents by increasing the number of current filaments and reducing the current density at the contact electrodes in a controlled manner. Furthermore, the improved switch can mitigate the degradation of switching conditions with increased number of firings of the switch.

  10. Combination of valproic acid and morpholino splice-switching oligonucleotide produces improved outcomes in spinal muscular atrophy patient-derived fibroblasts.

    PubMed

    Farrelly-Rosch, Anna; Lau, Chew Ling; Patil, Nitin; Turner, Bradley J; Shabanpoor, Fazel

    2017-09-01

    Spinal muscular atrophy (SMA), the leading genetic cause of infant mortality worldwide, is characterised by the homozygous loss of the survival motor neuron 1 (SMN1) gene. The consequent degeneration of spinal motor neurons and progressive atrophy of voluntary muscle groups results in paralysis and eventually premature infantile death. Humans possess a second nearly identical copy of SMN1, known as SMN2. However, SMN2 produces only 10-20% functional SMN protein due to aberrant splicing of its pre-mRNA that leads to the exclusion of exon 7. This level of SMN is insufficient to rescue the phenotype. Recently developed splice-switching antisense oligonuclotides (SSO) have shown great promise in correcting the aberrant splicing of SMN2 towards producing functional SMN protein. Several FDA approved drugs are being repurposed for SMA treatment including valproic acid (VPA), a histone deacetylase inhibitor, which has been shown to increase overall SMN2 expression. In this study, we have characterised the effects of single and combined treatment of VPA and a SSO based on phosphorodiamidate morpholino oligomer (PMO) chemistry. We conjugated both VPA and PMO to a single cell-penetrating peptide (Apolipoprotein E (ApoE)) for their simultaneous intracellular delivery. Treatment of SMA Type I patient-derived fibroblasts with the conjugates showed no additive increase in the level of full-length SMN2 mRNA expression over both 4 and 16 h treatments indicating that conjugation of VPA to ApoE-PMO has limited benefit. However, treatment with a combination of VPA and ApoE-PMO induced more favourable splice switching activity than either agent alone, promoting exon 7 inclusion in SMN2 transcripts. Our results suggest that combination therapy of VPA and ApoE-PMO is superior in upregulating SMN2 production in vitro, as compared to singular treatment of each compound at both transcriptional and protein levels. This study provides the first indication of a novel dual therapy approach

  11. Optimization of health-care organization and perceived improvement of patient comfort by switching from intra-venous BU four-times-daily infusions to a once-daily administration scheme in adult hematopoietic stem cell recipients.

    PubMed

    Xhaard, A; Rzepecki, P; Valcarcel, D; Santarone, S; Fürst, S; Serrano, D; De Angelis, G; Krüger, W; Scheid, C

    2014-04-01

    Previous studies have shown an equivalent pharmacokinetic profile between four-times-daily (4QD) and once-daily (QD) administration of intra-venous (IV) BU, without increased toxicity. We assess the impact of a switch in IV BU from a 4QD to a QD schedule, in terms of health-care organization, staff working conditions, quality of care dispensed and perceived patient comfort. Clinicians, nurses and pharmacists from nine allogeneic transplantation units in five European countries were interviewed face to face. Overall perception of QD versus 4QD BU was very positive. Both administration schemes were evaluated to be equally efficaciousZ. QD BU was perceived to be safer and more convenient. Clinicians and nurses perceived that patient comfort was improved, due to fewer complications associated with repeated infusions, and avoiding night infusions associated with stress, anxiety and decreased quality of sleep. Switching from 4QD to QD BU had a significant impact on health-care organization, with a better integration in the overall management and usual timelines in the pharmacies and transplantation units. Time spent to prepare and administer BU was significantly reduced, leading to potential financial savings that merit further assessment and would be of particular interest in the current economic climate.

  12. Performance issues in SCM label switched networks due to tunable laser switching events

    NASA Astrophysics Data System (ADS)

    Smyth, F.; Barry, L. P.

    2006-09-01

    Optical Packet Switched (OPS) networks employing Optical Label Switching (OLS) techniques have the potential to enable an all-optical internet. In these networks, data remains in optical format throughout the entire network and routing is performed using a separate optical label. The label information is used to control fast tunable lasers that will transfer data packets to different wavelengths for routing and contention resolution. In this paper we investigate interference between subcarrier multiplexed (SCM) labels in such a network, due to switching events in the tunable laser transmitter. This interference may place a limitation on the channel spacing and subcarrier frequency used. Two 50GHz spaced optical carriers were modulated with 2.5Gbit/s SCM labels at 20GHz. Bit error rate measurements were taken with two lasers fixed 50 GHz apart, and also with one of the lasers (an SG-DBR) switching between this channel and another one 800GHz away. When the SG-DBR laser is not switching, a power penalty of approximately 0.25 dB is introduced due to interference through the optical filter. However, when the SG-DBR laser is switching between wavelengths an error floor of 1x10-5 is introduced due to the time it takes the tunable laser to settle to its target channel. In a systems application, this would result in packets being incorrectly routed.

  13. Asymmetrical Switch Costs in Children

    ERIC Educational Resources Information Center

    Ellefson, Michelle R.; Shapiron, Laura R.; Chater, Nick

    2006-01-01

    Switching between tasks produces decreases in performance as compared to repeating the same task. Asymmetrical switch costs occur when switching between two tasks of unequal difficulty. This asymmetry occurs because the cost is greater when switching to the less difficult task than when switching to the more difficult task. Various theories about…

  14. Improvement of MBD parameters in dialysis patients by a switch to, and combined use of lanthanum carbonate: Josai Dialysis Forum collaborative study.

    PubMed

    Shinoda, Toshio; Yamasaki, Masahiro; Chida, Yoshiko; Takagi, Masao; Tanaka, Yoshiko; Ando, Ryoichi; Suzuki, Toshiaki; Tagawa, Hitoshi

    2013-04-01

    The effects of lanthanum carbonate on MBD parameters were investigated in 59 hemodialysis patients who were taking calcium carbonate. Lanthanum carbonate (initial dosage: 750 mg/day), as a replacement for or in combination with calcium carbonate and/or sevelamer hydrochloride, was administered for 12 months with increase/decrease of dosages. Lanthanum carbonate replaced calcium carbonate for 21 cases and was co-administered in 38 cases. It replaced sevelamer hydrochloride in 20 cases and was co-administered in 10 cases. Both the number of cases to which calcium carbonate was administered and their dosages decreased to about 70-80% 12 months after the initiation, and cases administered sevelamer decreased to about 30%. In the cases for which lanthanum carbonate was co-administered, the dosages of calcium carbonate and sevelamer slightly decreased. A significant decrease in serum calcium level was observed. In the serum phosphorus levels (P levels), significant decrease compared with the initial level was observed only at six and nine months. Intact parathyroid hormone (iPTH) level remained stable at around 230 pg/mL without significant change. The dosage of vitamin D and cinacalcet remained without significant change. The results of this trial suggest that, if dosages of vitamin D and cinacalcet are adequately controlled, a switch to lanthanum carbonate and its concomitant use are effective to control the Ca and P levels without changing iPTH levels.

  15. High on/off capacitance ratio RF MEMS capacitive switches

    NASA Astrophysics Data System (ADS)

    Wei, Hao; Deng, Zhongliang; Guo, Xubing; Wang, Yucheng; Yang, Hongtao

    2017-05-01

    In this paper, high on/off capacitance ratio radio frequency micro-electro-mechanical-systems (RF MEMS) switches are designed, fabricated, measured and analyzed. Two types of RF MEMS switches, a shunt switch with a contact point and an inline switch without a contact point, are presented. Metal-insulator-metal (MIM) fixed capacitors are used in the MEMS switches. The electrode topologies of RF MEMS switches are analyzed. The parameter λ is defined to describe the relationship between the capacitance ratio, the height of the beam and the actuation voltage. The measured results indicate that, for MEMS switch #1 with a contact point and gap of 1 µm, the insertion loss is better than 0.64 dB up to 40 GHz, and the isolation is more than 20 dB from 11.28 to 30.38 GHz with an actuation voltage of 42 V. For the inline MEMS with a displacement of 1.5 µm, the insertion loss is better than 0.56 dB up to 40 GHz, and the isolation is more than 20 dB from 4.45 to 30.48 GHz with an actuation voltage of 36 V. Circuit models and measured results of the proposed MEMS switches show good agreement. From the fitted results, the on/off capacitance ratio is ~227 for the MEMS switch #1 and ~313 for the MEMS switch #2, respectively. Compared with traditional MEMS capacitive switches with dielectric material Si3N4 and a relatively lower gap (1.5 µm), the proposed MEMS switches exhibit high on/off capacitance ratios.

  16. Quantum cryptography without switching.

    PubMed

    Weedbrook, Christian; Lance, Andrew M; Bowen, Warwick P; Symul, Thomas; Ralph, Timothy C; Lam, Ping Koy

    2004-10-22

    We propose a new coherent state quantum key distribution protocol that eliminates the need to randomly switch between measurement bases. This protocol provides significantly higher secret key rates with increased bandwidths than previous schemes that only make single quadrature measurements. It also offers the further advantage of simplicity compared to all previous protocols which, to date, have relied on switching.

  17. Power-Switching Circuit

    NASA Technical Reports Server (NTRS)

    Praver, Gerald A.; Theisinger, Peter C.; Genofsky, John

    1987-01-01

    Functions of circuit breakers, meters, and switches combined. Circuit that includes power field-effect transistors (PFET's) provides on/off switching, soft starting, current monitoring, current tripping, and protection against overcurrent for 30-Vdc power supply at normal load currents up to 2 A. Has no moving parts.

  18. Reflective HTS switch

    DOEpatents

    Martens, J.S.; Hietala, V.M.; Hohenwarter, G.K.G.

    1994-09-27

    A HTS (High Temperature Superconductor) switch includes a HTS conductor for providing a superconducting path for an electrical signal and an serpentine wire actuator for controllably heating a portion of the conductor sufficiently to cause that portion to have normal, and not superconducting, resistivity. Mass of the portion is reduced to decrease switching time. 6 figs.

  19. Reflective HTS switch

    SciTech Connect

    Martens, Jon S.; Hietala, Vincent M.; Hohenwarter, Gert K. G.

    1994-01-01

    A HTS switch includes a HTS conductor for providing a superconducting path for an electrical signal and an serpentine wire actuator for controllably heating a portion of the conductor sufficiently to cause that portion to have normal, and not superconducting, resistivity. Mass of the portion is reduced to decrease switching time.

  20. Manually operated coded switch

    DOEpatents

    Barnette, Jon H.

    1978-01-01

    The disclosure relates to a manually operated recodable coded switch in which a code may be inserted, tried and used to actuate a lever controlling an external device. After attempting a code, the switch's code wheels must be returned to their zero positions before another try is made.

  1. Fixed solar collection system

    SciTech Connect

    Tipton, H.R.

    1984-07-31

    A fixed solar energy collector system has facing panels of different size forming a Vee-shaped trough open at its base and supporting a plurality of highly reflective convex reflectors strategically disposed upon said panels in reflective relationship to a plurality of Fresnel lenses positioned at the base of the trough. A suitable reflector, disposed beneath the Fresnel lenses, directs the reflected energy to a heat-needy target.

  2. Fixed pitch wind turbines

    NASA Technical Reports Server (NTRS)

    Fenn, D. B.; Viterna, L. A.

    1978-01-01

    Wind turbines designed for fixed pitch operation offer potential reductions in the cost of the machine by eliminating many costly components. It was shown that a rotor can be designed which produces the same energy annually as Mod-0 but which regulates its power automatically by progressively stalling the blades as wind speed increases. Effects of blade twist, taper, root cutout, and airfoil shape on performance are discussed as well as various starting technqiues.

  3. Neutrophilic Fixed Drug Eruption.

    PubMed

    Waldman, Leah; Reddy, Swathi B; Kassim, Andrea; Dettloff, Jennifer; Reddy, Vijaya B

    2015-07-01

    Fixed drug eruption (FDE) is a cutaneous reaction to a medication that recurs in the same fairly localized site with each exposure to the offending drug. The classical histopathologic findings in FDE consist of an interface dermatitis with predominantly lymphocytic inflammatory cell infiltrate. An unusual case of FDE in a 27-year-old pregnant woman who presented with widespread lesions and a predominantly neutrophilic infiltrate on histopathologic examination is reported.

  4. A Novel Molecular Switch

    PubMed Central

    Daber, Robert; Lewis, Mitchell

    2009-01-01

    Transcriptional regulation is a fundamental process for regulating the flux of all metabolic pathways. For the last several decades, the lac operon has served as a valuable model for studying transcription. More recently, the switch that controls the operon has also been successfully adapted to function in mammalian cells. Here we describe how, using directed evolution, we have created a novel switch that recognizes an asymmetric operator sequence. The new switch has a repressor with altered headpiece domains for operator recognition, and a redesigned dimer interface to create a heterodimeric repressor. Quite unexpectedly, the heterodimeric switch functions better than the natural system. It can repress more tightly than the naturally occurring switch of the lac operon; it is less leaky and can be induced more efficiently. Ultimately these novel repressors could be evolved to recognize eukaryotic promoters and used to regulate gene expression in mammalian systems. PMID:19540845

  5. Erected mirror optical switch

    DOEpatents

    Allen, James J.

    2005-06-07

    A microelectromechanical (MEM) optical switching apparatus is disclosed that is based on an erectable mirror which is formed on a rotatable stage using surface micromachining. An electrostatic actuator is also formed on the substrate to rotate the stage and mirror with a high angular precision. The mirror can be erected manually after fabrication of the device and used to redirect an incident light beam at an arbitrary angel and to maintain this state in the absence of any applied electrical power. A 1.times.N optical switch can be formed using a single rotatable mirror. In some embodiments of the present invention, a plurality of rotatable mirrors can be configured so that the stages and mirrors rotate in unison when driven by a single micromotor thereby forming a 2.times.2 optical switch which can be used to switch a pair of incident light beams, or as a building block to form a higher-order optical switch.

  6. RF Reference Switch for Spaceflight Radiometer Calibration

    NASA Technical Reports Server (NTRS)

    Knuble, Joseph

    2013-01-01

    The goal of this technology is to provide improved calibration and measurement sensitivity to the Soil Moisture Active Passive Mission (SMAP) radiometer. While RF switches have been used in the past to calibrate microwave radiometers, the switch used on SMAP employs several techniques uniquely tailored to the instrument requirements and passive remote-sensing in general to improve radiometer performance. Measurement error and sensitivity are improved by employing techniques to reduce thermal gradients within the device, reduce insertion loss during antenna observations, increase insertion loss temporal stability, and increase rejection of radar and RFI (radio-frequency interference) signals during calibration. The two legs of the single-pole double-throw reference switch employ three PIN diodes per leg in a parallel-shunt configuration to minimize insertion loss and increase stability while exceeding rejection requirements at 1,413 MHz. The high-speed packaged diodes are selected to minimize junction capacitance and resistance while ensuring the parallel devices have very similar I-V curves. Switch rejection is improved by adding high-impedance quarter-wave tapers before and after the diodes, along with replacing the ground via of one diode per leg with an open circuit stub. Errors due to thermal gradients in the switch are reduced by embedding the 50-ohm reference load within the switch, along with using a 0.25-in. (approximately equal to 0.6-cm) aluminum prebacked substrate. Previous spaceflight microwave radiometers did not embed the reference load and thermocouple directly within the calibration switch. In doing so, the SMAP switch reduces error caused by thermal gradients between the load and switch. Thermal issues are further reduced by moving the custom, highspeed regulated driver circuit to a physically separate PWB (printed wiring board). Regarding RF performance, previous spaceflight reference switches have not employed high-impedance tapers to improve

  7. Improved control of osteoarthritis pain and self-reported health status in non-responders to celecoxib switched to rofecoxib: results of PAVIA, an open-label post-marketing survey in Spain.

    PubMed

    Collantes-Estevez, Eduardo; Fernandez-Perez, Cristina

    2003-01-01

    An open-label multicentre study was conducted in primary care centres in Spain to investigate the effect of a switch from celecoxib to rofecoxib among patients with osteoarthritis and to identify factors associated with a good response to rofecoxib treatment. Patients were eligible to participate in this study if their physicians considered that they might benefit from such a change of therapy. A total of 2,228 patients (1481 women) were enrolled in the study: participants' mean age was 66.37 years (SD 9.04). Mean duration of OA was 7.44 (6.38) years. Predominant sites of OA included the knee (1,132 patients, 50.8%), lumbar spine (977 patients, 43.9%) and cervical spine (739 patients, 33.2%). At baseline, most patients (77%) were being prescribed celecoxib 200 mg/day; during the study most (92.5%) received rofecoxib 25 mg/day. The mean interval between switch to rofecoxib and follow-up interview was 33 days. Patients considered the therapeutic response to rofecoxib substantially and significantly superior to that previously obtained with celecoxib for the management of OA-related pain and OA-related health status (p < 0.001). Seventy-two percent of patients classified their response to rofecoxib therapy as 'good' or 'very good' (vs 6.6% of patients at baseline with celecoxib) and 89.3% of patients expressed satisfaction with rofecoxib (vs 28.9% at baseline with celecoxib). Improvements reported in patient self-assessments following rofecoxib therapy were complemented by similar changes in physician perceptions. The number of patients considered by their doctors to have 'good' or 'very good' OA-related health status rose from 10.1% at baseline to 80.0% on completion of rofecoxib therapy. Ancillary indices such as the proportion of patients with self-reported depression were also favourably influenced by the switch to rofecoxib from celecoxib. Determinants of response: Patient characteristics identified in multivariate analysis as predictive of a favourable response

  8. Shape-Memory Hydrogels: Evolution of Structural Principles To Enable Shape Switching of Hydrophilic Polymer Networks.

    PubMed

    Löwenberg, Candy; Balk, Maria; Wischke, Christian; Behl, Marc; Lendlein, Andreas

    2017-02-15

    The ability of hydrophilic chain segments in polymer networks to strongly interact with water allows the volumetric expansion of the material and formation of a hydrogel. When polymer chain segments undergo reversible hydration depending on environmental conditions, smart hydrogels can be realized, which are able to shrink/swell and thus alter their volume on demand. In contrast, implementing the capacity of hydrogels to switch their shape rather than volume demands more sophisticated chemical approaches and structural concepts. In this Account, the principles of hydrogel network design, incorporation of molecular switches, and hydrogel microstructures are summarized that enable a spatially directed actuation of hydrogels by a shape-memory effect (SME) without major volume alteration. The SME involves an elastic deformation (programming) of samples, which are temporarily fixed by reversible covalent or physical cross-links resulting in a temporary shape. The material can reverse to the original shape when these molecular switches are affected by application of a suitable stimulus. Hydrophobic shape-memory polymers (SMPs), which are established with complex functions including multiple or reversible shape-switching, may provide inspiration for the molecular architecture of shape-memory hydrogels (SMHs), but cannot be identically copied in the world of hydrophilic soft materials. For instance, fixation of the temporary shape requires cross-links to be formed also in an aqueous environment, which may not be realized, for example, by crystalline domains from the hydrophilic main chains as these may dissolve in presence of water. Accordingly, dual-shape hydrogels have evolved, where, for example, hydrophobic crystallizable side chains have been linked into hydrophilic polymer networks to act as temperature-sensitive temporary cross-links. By incorporating a second type of such side chains, triple-shape hydrogels can be realized. Considering the typically given light

  9. Optical packet switching

    NASA Astrophysics Data System (ADS)

    Shekel, Eyal; Ruschin, Shlomo; Majer, Daniel; Levy, Jeff; Matmon, Guy; Koenigsberg, Lisa; Vecht, Jacob; Geron, Amir; Harlavan, Rotem; Shfaram, Harel; Arbel, Arnon; McDermott, Tom; Brewer, Tony

    2005-02-01

    We report here a scalable, multichassis, 6.3 terabit core router, which utilizes our proprietary optical switch. The router is commercially available and deployed in several customer sites. Our solution combines optical switching with electronic routing. An internal optical packet switching network interconnects the router"s electronic line cards, where routing and buffering functions take place electronically. The system architecture and performance will be described. The optical switch is based on Optical Phased Array (OPA) technology. It is a 64 x 64, fully non-blocking, optical crossbar switch, capable of switching in a fraction of a nanosecond. The basic principles of operation will be explained. Loss and crosstalk results will be presented, as well as the results of BER measurements of a 160 Gbps transmission through one channel. Basic principles of operation and measured results will be presented for the burst-mode-receivers, arbitration algorithm and synchronization. Finally, we will present some of our current research work on a next-generation optical switch. The technological issues we have solved in our internal optical packet network can have broad applicability to any global optical packet network.

  10. Optical Circuit Switched Protocol

    NASA Technical Reports Server (NTRS)

    Monacos, Steve P. (Inventor)

    2000-01-01

    The present invention is a system and method embodied in an optical circuit switched protocol for the transmission of data through a network. The optical circuit switched protocol is an all-optical circuit switched network and includes novel optical switching nodes for transmitting optical data packets within a network. Each optical switching node comprises a detector for receiving the header, header detection logic for translating the header into routing information and eliminating the header, and a controller for receiving the routing information and configuring an all optical path within the node. The all optical path located within the node is solely an optical path without having electronic storage of the data and without having optical delay of the data. Since electronic storage of the header is not necessary and the initial header is eliminated by the first detector of the first switching node. multiple identical headers are sent throughout the network so that subsequent switching nodes can receive and read the header for setting up an optical data path.

  11. Intrinsic noise in systems with switching environments

    NASA Astrophysics Data System (ADS)

    Hufton, Peter G.; Lin, Yen Ting; Galla, Tobias; McKane, Alan J.

    2016-05-01

    We study individual-based dynamics in finite populations, subject to randomly switching environmental conditions. These are inspired by models in which genes transition between on and off states, regulating underlying protein dynamics. Similarly, switches between environmental states are relevant in bacterial populations and in models of epidemic spread. Existing piecewise-deterministic Markov process approaches focus on the deterministic limit of the population dynamics while retaining the randomness of the switching. Here we go beyond this approximation and explicitly include effects of intrinsic stochasticity at the level of the linear-noise approximation. Specifically, we derive the stationary distributions of a number of model systems, in good agreement with simulations. This improves existing approaches which are limited to the regimes of fast and slow switching.

  12. Multi-planed unified switching topologies

    DOEpatents

    Chen, Dong; Heidelberger, Philip; Sugawara, Yutaka

    2017-07-04

    An apparatus and method for extending the scalability and improving the partitionability of networks that contain all-to-all links for transporting packet traffic from a source endpoint to a destination endpoint with low per-endpoint (per-server) cost and a small number of hops. An all-to-all wiring in the baseline topology is decomposed into smaller all-to-all components in which each smaller all-to-all connection is replaced with star topology by using global switches. Stacking multiple copies of the star topology baseline network creates a multi-planed switching topology for transporting packet traffic. Point-to-point unified stacking method using global switch wiring methods connects multiple planes of a baseline topology by using the global switches to create a large network size with a low number of hops, i.e., low network latency. Grouped unified stacking method increases the scalability (network size) of a stacked topology.

  13. Precise Point Positioning with Partial Ambiguity Fixing.

    PubMed

    Li, Pan; Zhang, Xiaohong

    2015-06-10

    Reliable and rapid ambiguity resolution (AR) is the key to fast precise point positioning (PPP). We propose a modified partial ambiguity resolution (PAR) method, in which an elevation and standard deviation criterion are first used to remove the low-precision ambiguity estimates for AR. Subsequently the success rate and ratio-test are simultaneously used in an iterative process to increase the possibility of finding a subset of decorrelated ambiguities which can be fixed with high confidence. One can apply the proposed PAR method to try to achieve an ambiguity-fixed solution when full ambiguity resolution (FAR) fails. We validate this method using data from 450 stations during DOY 021 to 027, 2012. Results demonstrate the proposed PAR method can significantly shorten the time to first fix (TTFF) and increase the fixing rate. Compared with FAR, the average TTFF for PAR is reduced by 14.9% for static PPP and 15.1% for kinematic PPP. Besides, using the PAR method, the average fixing rate can be increased from 83.5% to 98.2% for static PPP, from 80.1% to 95.2% for kinematic PPP respectively. Kinematic PPP accuracy with PAR can also be significantly improved, compared to that with FAR, due to a higher fixing rate.

  14. Precise Point Positioning with Partial Ambiguity Fixing

    PubMed Central

    Li, Pan; Zhang, Xiaohong

    2015-01-01

    Reliable and rapid ambiguity resolution (AR) is the key to fast precise point positioning (PPP). We propose a modified partial ambiguity resolution (PAR) method, in which an elevation and standard deviation criterion are first used to remove the low-precision ambiguity estimates for AR. Subsequently the success rate and ratio-test are simultaneously used in an iterative process to increase the possibility of finding a subset of decorrelated ambiguities which can be fixed with high confidence. One can apply the proposed PAR method to try to achieve an ambiguity-fixed solution when full ambiguity resolution (FAR) fails. We validate this method using data from 450 stations during DOY 021 to 027, 2012. Results demonstrate the proposed PAR method can significantly shorten the time to first fix (TTFF) and increase the fixing rate. Compared with FAR, the average TTFF for PAR is reduced by 14.9% for static PPP and 15.1% for kinematic PPP. Besides, using the PAR method, the average fixing rate can be increased from 83.5% to 98.2% for static PPP, from 80.1% to 95.2% for kinematic PPP respectively. Kinematic PPP accuracy with PAR can also be significantly improved, compared to that with FAR, due to a higher fixing rate. PMID:26067196

  15. Improved polymerase chain reaction-based method to detect early-stage epitheliotropic T-cell lymphoma (mycosis fungoides) in formalin-fixed, paraffin-embedded skin biopsy specimens of the dog.

    PubMed

    Chaubert, Pascal; Baur Chaubert, Audrey S; Sattler, Ursula; Forster, Ursula; Bornand, Valérie; Suter, Maja; Welle, Monika

    2010-01-01

    In the dog, early-stage epitheliotropic T-cell lymphoma (ETCL) can clinically and histologically mimic a large range of inflammatory dermatoses and often progresses rapidly to a more aggressive tumor stage. Early diagnosis of ETCL is essential to proceed with a specific oncologic therapy that is favorable for the prognosis. In the present study, an improved method for the detection of T-cell receptor gamma (TCRgamma) rearrangement was developed by designing a new set of consensus primers to amplify the different forms of rearranged canine TCRgamma gene sequences by polymerase chain reaction. The amplicons were analyzed by conventional polyacrylamide gel electrophoresis, which requires minimal specific equipment and may be performed in almost every pathology laboratory at low costs. The method proved to be highly specific and sensitive to detect early ETCL in formalin-fixed, paraffin-embedded biopsy specimens, providing an efficient tool for veterinary pathologists to distinguish early neoplastic from reactive cutaneous T-cell infiltrates (tumor-specific marker) or to discriminate T-cell lymphoma from B-cell lymphomas or nonlymphoid neoplasms (T-cell lineage marker). By direct sequencing analysis of amplified TCRgamma gene sequences, ETCL was found to rearrange exclusively the joining (J) 4 region, which suggests specific biology for primary cutaneous T-cell lymphomas. Also, a novel (seventh) functional J region in the TCRgamma gene, localized approximately 2.3 kb upstream of J5, was identified.

  16. The Aerosol Foam Formulation of the Fixed Combination Calcipotriene Plus Betamethasone Dipropionate Improves the Health-Related Quality of Life in Patients With Psoriasis Vulgaris: Results from the Randomized PSO-FAST Study.

    PubMed

    Leonardi, Craig; Bagel, Jerry; Yamauchi, Paul; Pariser, David; Xu, Zhenyi; Moller, Anders; Osterdal, Marie Louise; Stein Gold, Linda

    2016-08-01

    Psoriasis has a major impact on patient quality of life, similar to that seen in other chronic diseases, eg, diabetes. Health-related quality of life (HRQoL) measures are commonly included in clinical trial designs, capturing the disease burden and therapeutic success of a treatment. In the randomized, double-blind, phase III PSO-FAST (Psoriasis vulgaris, a Four-week, vehicle-controlled, efficacy And Safety Trial) study (nCT01866163), fixed combination calcipotriene (Cal) 0.005% plus betamethasone dipropionate (BD) 0.064% aerosol foam was compared with vehicle. By treatment end, 53% of patients using Cal/BD foam achieved treatment success.
    To compare the impact on HRQoL of Cal/BD foam vs vehicle in patients with mild-to-severe psoriasis.
    HRQoL was assessed by dermatology life-quality index (DLQI; baseline, weeks 1, 2, 4) and EQ-5D-5L (EQ-5D; baseline, week 4) questionnaires. A DLQI score of 0 (range, 0-30) indicates no effect on the patient's life; an EQ-5D utility score of 1 (range, 0-1) and an EQ-5D visual analog scale (VAS) score of 100 (range, 1-100) indicate perfect health.
    426 patients were randomized (Cal/BD foam, n=323; vehicle, n=103). Baseline mean DLQI scores were 9.9 (Cal/BD foam) and 10.3 (vehicle). The impact of psoriasis on HRQoL (EQ-5D utility score) at baseline was primarily driven by pain/discomfort (Cal/BD foam: 69.9%; vehicle: 65.0%) and anxiety/depression (Cal/BD foam: 45.3%; vehicle 44.7%). There was a greater improvement from baseline in DLQI score for Cal/BD foam vs vehicle at week 4 (-7.0 vs -4.4; P<.001); increased improvement was also seen in EQ-5D scores. At week 4, 48.1% of patients using Cal/BD foam reported no effect of psoriasis on their lives (DLQI = 0/1), and of patients using Cal/BD foam with baseline DLQI scores ≥5, 81.2% achieved a ≥5-point improvement.
    Cal/BD aerosol foam improved HRQoL after 4 weeks, with most patients experiencing a clinically meaningful improvement and almost 50

  17. Electromechanical magnetization switching

    SciTech Connect

    Chudnovsky, Eugene M.; Jaafar, Reem

    2015-03-14

    We show that the magnetization of a torsional oscillator that, in addition to the magnetic moment also possesses an electrical polarization, can be switched by the electric field that ignites mechanical oscillations at the frequency comparable to the frequency of the ferromagnetic resonance. The 180° switching arises from the spin-rotation coupling and is not prohibited by the different symmetry of the magnetic moment and the electric field as in the case of a stationary magnet. Analytical equations describing the system have been derived and investigated numerically. Phase diagrams showing the range of parameters required for the switching have been obtained.

  18. Sleep State Switching

    PubMed Central

    Saper, Clifford B.; Fuller, Patrick M.; Pedersen, Nigel P.; Lu, Jun; Scammell, Thomas E.

    2010-01-01

    We take for granted the ability to fall asleep or to snap out of sleep into wakefulness, but these changes in behavioral state require specific switching mechanisms in the brain that allow well-defined state transitions. In this review, we examine the basic circuitry underlying the regulation of sleep and wakefulness, and discuss a theoretical framework wherein the interactions between reciprocal neuronal circuits enable relatively rapid and complete state transitions. We also review how homeostatic, circadian, and allostatic drives help regulate sleep state switching, and discuss how breakdown of the switching mechanism may contribute to sleep disorders such as narcolepsy. PMID:21172606

  19. Photoconductive switch package

    DOEpatents

    Ca[rasp, George J

    2013-10-22

    A photoconductive switch is formed of a substrate that has a central portion of SiC or other photoconductive material and an outer portion of cvd-diamond or other suitable material surrounding the central portion. Conducting electrodes are formed on opposed sides of the substrate, with the electrodes extending beyond the central portion and the edges of the electrodes lying over the outer portion. Thus any high electric fields produced at the edges of the electrodes lie outside of and do not affect the central portion, which is the active switching element. Light is transmitted through the outer portion to the central portion to actuate the switch.

  20. Photoconductive switch package

    DOEpatents

    Caporaso, George J.

    2015-10-27

    A photoconductive switch is formed of a substrate that has a central portion of SiC or other photoconductive material and an outer portion of cvd-diamond or other suitable material surrounding the central portion. Conducting electrodes are formed on opposed sides of the substrate, with the electrodes extending beyond the central portion and the edges of the electrodes lying over the outer portion. Thus any high electric fields produced at the edges of the electrodes lie outside of and do not affect the central portion, which is the active switching element. Light is transmitted through the outer portion to the central portion to actuate the switch.

  1. Solid state switch

    DOEpatents

    Merritt, B.T.; Dreifuerst, G.R.

    1994-07-19

    A solid state switch, with reverse conducting thyristors, is designed to operate at 20 kV hold-off voltage, 1,500 A peak, 1.0 [mu]s pulsewidth, and 4,500 pps, to replace thyratrons. The solid state switch is more reliable, more economical, and more easily repaired. The switch includes a stack of circuit card assemblies, a magnetic assist and a trigger chassis. Each circuit card assembly contains a reverse conducting thyristor, a resistor capacitor network, and triggering circuitry. 6 figs.

  2. Fixed solar energy concentrator

    SciTech Connect

    Houghton, A.J.; Knasel, T.M.

    1981-01-20

    An apparatus for the concentration of solar energy upon a fixed array of solar cells is disclosed. A transparent material is overlayed upon the cell array, and a diffuse reflective coating is applied to the surface area of the transparent medium in between cells. Radiant light, which reflects through the transparent layer and does not fall directly incident to a cell surface is reflected by the coating layer in an approximate cosine pattern. Thereafter, such light undergoes internal reflection and rediffusion until subsequently it either strikes a solar cell surface or is lost through the upper surface of the transparent material.

  3. Micromagnetics: Modeling and application to switching

    NASA Astrophysics Data System (ADS)

    Apalkov, Dmytro

    2005-11-01

    This dissertation describes several projects related to micromagnetic simulations of magnetization dynamics. In the first part we will describe several improvements implemented in the micromagnetics code that has been developed by our research group. The most time-consuming part of a micromagnetic calculation is the computation of the magnetostatic field at each computational cell due to each of the other cells. Straightforward calculation requires a time of order N2, where N is the number of cells in the system. There are several methods to decrease the calculation time: Ewald summation, Fast Fourier transform and Fast Multipole method (FMM). The last has several advantages over the first two: the computation time is proportional to N and the method does not impose any additional requirements, such as a regular grid of cells, on the system. However, the adoption of the FMM by the micromagnetic community has been slowed because of some problems in its conventional implementation, such as complexity and difficulty in treatment of nearby cells and boundary conditions. This dissertation describes the solution to these problems. An important characteristic of a recording process is the switching time, which shows how long it takes to write a bit of information. Switching via spin-wave instability is one of the fastest switching mechanisms, which is not fully understood. This part of the dissertation studies this type of switching applied to longitudinal switching, in which the magnetization of the bit lies in the plane of the film, and perpendicular switching, in which the magnetization is perpendicular to the plane of a thin magnetic film. A new visualization scheme, which quantifies the spin-wave instability for each possible wave vector, is introduced and used to study the magnetization dynamics during switching. The third part of the dissertation deals with a very new and promising type of switching, which occurs when an electric current is passed between two

  4. Modelling, analyses and design of switching converters

    NASA Technical Reports Server (NTRS)

    Cuk, S. M.; Middlebrook, R. D.

    1978-01-01

    A state-space averaging method for modelling switching dc-to-dc converters for both continuous and discontinuous conduction mode is developed. In each case the starting point is the unified state-space representation, and the end result is a complete linear circuit model, for each conduction mode, which correctly represents all essential features, namely, the input, output, and transfer properties (static dc as well as dynamic ac small-signal). While the method is generally applicable to any switching converter, it is extensively illustrated for the three common power stages (buck, boost, and buck-boost). The results for these converters are then easily tabulated owing to the fixed equivalent circuit topology of their canonical circuit model. The insights that emerge from the general state-space modelling approach lead to the design of new converter topologies through the study of generic properties of the cascade connection of basic buck and boost converters.

  5. Solar array switching unit

    NASA Technical Reports Server (NTRS)

    Craig, Jr., Calvin L. (Inventor)

    2000-01-01

    A solar array switching (SASU) unit (22) according to the present invention includes a control system (24), a solar cell array (26) and switch circuits (28). The SASU unit (22) is associated with a power card (30) for receiving an output from the array (26). The array (26) has a number (0.5Y) of rows (38) each of which includes a pair of cell strings (42) separated by one of the switch circuits (28). Each of the strings (42) includes a number (X) of cells in electrical series. The SASU (22) switches the array (26) between a short string configuration where the array (26) effectively includes Y strings of X length, and a long string configuration where the array (26) effectively includes 0.5Y strings of 2X length. The SASU (22) thereby facilitates the use of solar power for space missions where solar intensity, operating temperature or other factors vary significantly.

  6. Plasmonic enhanced ultrafast switch.

    SciTech Connect

    Subramania,Ganapathi Subramanian; Reno, John Louis; Passmore, Brandon Scott; Harris, Tom.; Shaner, Eric Arthur; Barrick, Todd A.

    2009-09-01

    Ultrafast electronic switches fabricated from defective material have been used for several decades in order to produce picosecond electrical transients and TeraHertz radiation. Due to the ultrashort recombination time in the photoconductor materials used, these switches are inefficient and are ultimately limited by the amount of optical power that can be applied to the switch before self-destruction. The goal of this work is to create ultrafast (sub-picosecond response) photoconductive switches on GaAs that are enhanced through plasmonic coupling structures. Here, the plasmonic coupler primarily plays the role of being a radiation condenser which will cause carriers to be generated adjacent to metallic electrodes where they can more efficiently be collected.

  7. An optical switch

    DOEpatents

    Christophorou, L.G.; Hunter, S.R.

    1987-04-30

    The invention is a gas mixture for a diffuse discharge switch having an electron attaching gas wherein electron attachment is brought about by indirect excitation of molecules to long live states by exposure to laser light. 3 figs.

  8. Switching and stopping antidepressants

    PubMed Central

    Keks, Nicholas; Hope, Judy; Keogh, Simone

    2016-01-01

    SUMMARY Switching from one antidepressant to another is frequently indicated due to an inadequate treatment response or unacceptable adverse effects. All antidepressant switches must be carried out cautiously and under close observation. Conservative switching strategies involve gradually tapering the first antidepressant followed by an adequate washout period before the new antidepressant is started. This can take a long time and include periods of no treatment with the risk of potentially life-threatening exacerbations of illness. Clinical expertise is needed for more rapid or cross-taper switching as drug toxicity, including serotonin syndrome, may result from inappropriate co-administration of antidepressants. Some antidepressants must not be combined. Antidepressants can cause withdrawal syndromes if discontinued abruptly after prolonged use. Relapse and exacerbation of depression can also occur. Gradual dose reduction over days to weeks reduces the risk and severity of complications. PMID:27346915

  9. Optical fiber crossbar switch

    NASA Astrophysics Data System (ADS)

    Kilcoyne, Michael K.; Beccue, Stephen M.; Brar, Berinder; Robinson, G.; Pedrotti, Kenneth D.; Haber, William A.

    1990-07-01

    Advances in high performance computers and signal processing systems have led to parallel system architectures. The main limitation in achieving the performance expected of these parallel systems has been the realization of an efficient means to interconnect many processors into a effective parallel system. Electronic interconnections have proved cumbersome, costly and ineffective. The Optical Fiber Crossbar Switch (OFCS) is a compact low power, multi-gigahertz bandwidth multi-channel switch which can be used in large scale computer and telecommunication applications. The switch operates in the optical domain using GaAs semiconductor lasers to transmit wideband multiple channel optical data over fiber optic cables. Recently, a 32 X 32 crossbar switching system was completed and demonstrated. Error free performance was obtained at a data bandwidth of 410 MBPS, using a silicon switch IC. The switch can be completely reconfigured in less than 50 nanoseconds under computer control. The fully populated OFCS has the capability to handle 12.8 gigabits per second (GBPS) of data while switching this data over 32 channels without the loss of a single bit during switching. GaAs IC technology has now progressed to the point that 16 X 16 GaAs based crossbar switch Ics are available which have increased the data bandwidth capability to 2.4 GBPS. The present optical interfaces are integrated GaAs transmitter drivers, GaAs lasers, and integrated GaAs optical receivers with data bandwidths exceeding 2.4 GBPS. A system using all Ill-V switching and optoelectronic components is presently under development for both NASA and DoD programs. The overall system is designed to operate at 1.3 GBPS. It is expected that these systems will find wide application in high capacity computing systems based on parallel microprocessor architecture which require high data bandwidth communication between processors. The OFCS will also have application in commercial optical telecommunication systems

  10. Cygnus PFL Switch Jitter

    SciTech Connect

    C. Mitton, G. Corrow, M. Hansen, D. Henderson, et al.

    2007-07-21

    The Cygnus Dual Beam Radiographic Facility consists of two identical radiographic sources: Cygnus 1 and Cygnus 2. Each source has the following X-ray output: 1-mm diameter spot size, 4 rads at 1 m, 50-ns full-widthhalf-maximum. The diode pulse has the following electrical specifications: 2.25 MV, 60 kA, 60 ns. This Radiographic Facility is located in an underground tunnel test area at the Nevada Test Site (NTS). The sources were developed to produce high-resolution images on subcritical tests performed at NTS. Subcritical tests are single-shot, high-value events. For this application, it is desirable to maintain a high level of reproducibility in source output. The major components of the Cygnus machines are Marx generator, water-filled pulse forming line (PFL), water-filled coaxial transmission line, threecell inductive voltage adder, and rod-pinch diode. A primary source of fluctuation in Cygnus shot-to-shot performance may be jitter in breakdown of the main PFL switch, which is a “self-break” switch. The PFL switch breakdown time determines the peak PFL charging voltage, which ultimately affects the source X-ray spectrum and dose. Therefore, PFL switch jitter may contribute to shot-to-shot variation in these parameters, which are crucial to radiographic quality. In this paper we will present PFL switch jitter analysis for both Cygnus machines and present the correlation with dose. For this analysis, the PFL switch on each machine was maintained at a single gap setting, which has been used for the majority of shots at NTS. In addition the PFL switch performance for one larger switch gap setting will be examined.

  11. uv preilluminated gas switches

    SciTech Connect

    Bradley, L.P.; Orham, E.L.; Stowers, I.F.; Braucht, J.R.

    1980-06-03

    We have designed, built, and characterized uv preilluminated gas switches for a trigger circuit and a low inductance discharge circuit. These switches have been incorporated into a 54 x 76 x 150 cm pulser module to produce a 1 Ma output current rising at 5 x 10/sup 12/ amps/sec with 1 ns jitter. Twenty such modules will be used on the Nova Inertial Confinement Fusion Laser System for plasma retropulse shutters.

  12. Cygnus Water Switch Jitter

    SciTech Connect

    Charles V. Mitton, George D. Corrow, Mark D. Hansen, David J. Henderson, et al.

    2008-03-01

    The Cygnus Dual Beam Radiographic Facility consists of two identical radiographic sources - Cygnus 1 and Cygnus 2. Each source has the following x-ray output: 1-mm diameter spot size, 4 rad at 1 m, 50-ns Full Width Half Max. The diode pulse has the following electrical specifications: 2.25 MV, 60 kA, 60 ns. This Radiographic Facility is located in an underground tunnel test area at the Nevada Test Site (NTS). The sources were developed to produce high-resolution images on subcritical tests which are performed at NTS. Subcritical tests are single-shot, high-value events. For this application, it is desirable to maintain a high level of reproducibility in source output. The major components of the Cygnus machines are: Marx generator, water-filled pulse–forming line (PFL), water-filled coaxial transmission line, three-cell inductive voltage adder, and rod-pinch diode. A primary source of fluctuation in Cygnus shot-to-shot performance is jitter in breakdown of the main PFL switch, which is a “self-break” switch. The PFL switch breakdown time determines the peak PFL charging voltage, which ultimately affects the diode pulse. Therefore, PFL switch jitter contributes to shot-to-shot variation in source endpoint energy and dose. In this paper we will present PFL switch jitter analysis for both Cygnus machines and give the correlation with diode performance. For this analysis the PFL switch on each machine was maintained at a single gap setting which has been used for the majority of shots at NTS. In addition to this analysis, PFL switch performance for different switch gap settings taken recently will be examined. Lastly, implications of source jitter for radiographic diagnosis of subcritical shots will be discussed.

  13. Multi-mode sliding mode control for precision linear stage based on fixed or floating stator.

    PubMed

    Fang, Jiwen; Long, Zhili; Wang, Michael Yu; Zhang, Lufan; Dai, Xufei

    2016-02-01

    This paper presents the control performance of a linear motion stage driven by Voice Coil Motor (VCM). Unlike the conventional VCM, the stator of this VCM is regulated, which means it can be adjusted as a floating-stator or fixed-stator. A Multi-Mode Sliding Mode Control (MMSMC), including a conventional Sliding Mode Control (SMC) and an Integral Sliding Mode Control (ISMC), is designed to control the linear motion stage. The control is switched between SMC and IMSC based on the error threshold. To eliminate the chattering, a smooth function is adopted instead of a signum function. The experimental results with the floating stator show that the positioning accuracy and tracking performance of the linear motion stage are improved with the MMSMC approach.

  14. Multi-mode sliding mode control for precision linear stage based on fixed or floating stator

    NASA Astrophysics Data System (ADS)

    Fang, Jiwen; Long, Zhili; Wang, Michael Yu; Zhang, Lufan; Dai, Xufei

    2016-02-01

    This paper presents the control performance of a linear motion stage driven by Voice Coil Motor (VCM). Unlike the conventional VCM, the stator of this VCM is regulated, which means it can be adjusted as a floating-stator or fixed-stator. A Multi-Mode Sliding Mode Control (MMSMC), including a conventional Sliding Mode Control (SMC) and an Integral Sliding Mode Control (ISMC), is designed to control the linear motion stage. The control is switched between SMC and IMSC based on the error threshold. To eliminate the chattering, a smooth function is adopted instead of a signum function. The experimental results with the floating stator show that the positioning accuracy and tracking performance of the linear motion stage are improved with the MMSMC approach.

  15. Finding a stabilising switching law for switching nonlinear models

    NASA Astrophysics Data System (ADS)

    Lendek, Zs.; Raica, P.; Lauber, J.; Guerra, T. M.

    2016-09-01

    This paper considers the stabilisation of switching nonlinear models by switching between the subsystems. We assume that arbitrary switching between two subsystems is possible once a subsystem has been active for a predefined number of samples. We use a Takagi-Sugeno representation of the models and a switching Lyapunov function is employed to develop sufficient stability conditions. If the conditions are satisfied, we construct a switching law that stabilises the system. The application of the conditions is illustrated in several examples.

  16. The minimum requirements of language control: evidence from sequential predictability effects in language switching.

    PubMed

    Declerck, Mathieu; Koch, Iring; Philipp, Andrea M

    2015-03-01

    The current study systematically examined the influence of sequential predictability of languages and concepts on language switching. To this end, 2 language switching paradigms were combined. To measure language switching with a random sequence of languages and/or concepts, we used a language switching paradigm that implements visual cues and stimuli. The other paradigm implements a fixed sequence of languages and/or concepts to measure predictable language switching. Four experiments that used these 2 paradigms showed that switch costs were smaller when both the language and concept were predictably known, whereas no overall switch cost reduction was found when just the language or concept was predictable. These results indicate that knowing both language and concept (i.e., response) can resolve language interference. However, interference resolution does not start solely based on the knowledge of which concept or language one has to produce. We discuss how existent models should be revised to accommodate these results.

  17. The PPAR α / γ Agonist, Tesaglitazar, Improves Insulin Mediated Switching of Tissue Glucose and Free Fatty Acid Utilization In Vivo in the Obese Zucker Rat.

    PubMed

    Wallenius, Kristina; Kjellstedt, Ann; Thalén, Pia; Löfgren, Lars; Oakes, Nicholas D

    2013-01-01

    lean controls, obese controls, and obese rats treated with the dual peroxisome proliferator activated receptor (PPAR) α/γ agonist, tesaglitazar, 3  μ mol/kg/day for 3 weeks. Whole body glucose disposal rate (R d ) and hepatic glucose output (HGO) were assessed under basal fasting and hyperinsulinemic isoglycemic clamp conditions using [3,(3)H]glucose. Indices of tissue specific glucose utilization (R g ') were measured at basal, physiological, and supraphysiological levels of insulinemia using 2-deoxy-D-[2,6-(3)H]glucose. Finally, whole body and tissue specific FFA and glucose utilization and metabolic fate were evaluated under basal and hyperinsulinemic conditions using a combination of [U-(13)C]glucose, 2-deoxy-D-[U-(14)C]glucose, [U-(14)C]palmitate, and [9,10-(3)H]-(R)-bromopalmitate. Tesaglitazar improved whole body insulin action by greater suppression of HGO and stimulation of R d compared to obese controls. This involved increased insulin stimulation of R g ' in fat and skeletal muscle as well as increased glycogen synthesis. Tesaglitazar dramatically improved insulin mediated suppression of plasma FFA level, whole body turnover (R fa ), and muscle, liver, and fat utilization. At basal insulin levels, tesaglitazar failed to lower HGO or R fa compared to obese controls. In conclusion, the results demonstrate that tesaglitazar has a remarkable ability to improve insulin mediated control of glucose and FFA fluxes in obese Zucker rats.

  18. The PPARα/γ Agonist, Tesaglitazar, Improves Insulin Mediated Switching of Tissue Glucose and Free Fatty Acid Utilization In Vivo in the Obese Zucker Rat

    PubMed Central

    Wallenius, Kristina; Kjellstedt, Ann; Thalén, Pia; Löfgren, Lars; Oakes, Nicholas D.

    2013-01-01

    Metabolic flexibility was assessed in male Zucker rats: lean controls, obese controls, and obese rats treated with the dual peroxisome proliferator activated receptor (PPAR) α/γ agonist, tesaglitazar, 3 μmol/kg/day for 3 weeks. Whole body glucose disposal rate (R d) and hepatic glucose output (HGO) were assessed under basal fasting and hyperinsulinemic isoglycemic clamp conditions using [3,3H]glucose. Indices of tissue specific glucose utilization (R g′) were measured at basal, physiological, and supraphysiological levels of insulinemia using 2-deoxy-D-[2,6-3H]glucose. Finally, whole body and tissue specific FFA and glucose utilization and metabolic fate were evaluated under basal and hyperinsulinemic conditions using a combination of [U-13C]glucose, 2-deoxy-D-[U-14C]glucose, [U-14C]palmitate, and [9,10-3H]-(R)-bromopalmitate. Tesaglitazar improved whole body insulin action by greater suppression of HGO and stimulation of R d compared to obese controls. This involved increased insulin stimulation of R g′ in fat and skeletal muscle as well as increased glycogen synthesis. Tesaglitazar dramatically improved insulin mediated suppression of plasma FFA level, whole body turnover (R fa), and muscle, liver, and fat utilization. At basal insulin levels, tesaglitazar failed to lower HGO or R fa compared to obese controls. In conclusion, the results demonstrate that tesaglitazar has a remarkable ability to improve insulin mediated control of glucose and FFA fluxes in obese Zucker rats. PMID:24285952

  19. Photoactivation switch from type II to type I reactions by electron-rich micelles for improved photodynamic therapy of cancer cells under hypoxia.

    PubMed

    Ding, Huiying; Yu, Haijun; Dong, Ying; Tian, Ruhai; Huang, Gang; Boothman, David A; Sumer, Baran D; Gao, Jinming

    2011-12-20

    Photodynamic therapy (PDT) is an emerging clinical modality for the treatment of a variety of diseases. Most photosensitizers are hydrophobic and poorly soluble in water. Many new nanoplatforms have been successfully established to improve the delivery efficiency of PS drugs. However, few reported studies have investigated how the carrier microenvironment may affect the photophysical properties of photosensitizer (PS) drugs and subsequently, their biological efficacy in killing malignant cells. In this study, we describe the modulation of type I and II photoactivation processes of the photosensitizer, 5,10,15,20-tetrakis(meso-hydroxyphenyl)porphyrin (mTHPP), by the micelle core environment. Electron-rich poly(2-(diisopropylamino)ethyl methacrylate) (PDPA) micelles increased photoactivations from type II to type I mechanisms, which significantly increased the generation of O(2)(-) through the electron transfer pathway over (1)O(2) production through energy transfer process. The PDPA micelles led to enhanced phototoxicity over the electron-deficient poly(D,L-lactide) control in multiple cancer cell lines under argon-saturated conditions. These data suggest that micelle carriers may not only improve the bioavailability of photosensitizer drugs, but also modulate photophysical properties for improved PDT efficacy. Published by Elsevier B.V.

  20. Photoactivation Switch from Type II to Type I Reactions by Electron-Rich Micelles for Improved Photodynamic Therapy of Cancer Cells Under Hypoxia

    PubMed Central

    Ding, Huiying; Yu, Haijun; Dong, Ying; Tian, Ruhai; Huang, Gang; Boothman, David A.; Sumer, Baran D.; Gao, Jinming

    2011-01-01

    Photodynamic therapy (PDT) is an emerging clinical modality for the treatment of a variety of diseases. Most photosensitizers are hydrophobic and poorly soluble in water. Many new nanoplatforms have been successfully established to improve the delivery efficiency of PS drugs. However, few reported studies have investigated how the carrier microenvironment may affect the photophysical properties of PS drugs and subsequently, their biological efficacy in killing malignant cells. In this study, we describe the modulation of type I and II photoactivation processes of the photosensitizer, 5,10,15,20-tetrakis(meso-hydroxyphenyl)porphyrin (mTHPP), by the micelle core environment. Electron-rich poly(2-(diisopropylamino)ethyl methacrylate) (PDPA) micelles increased photoactivations from type II to type I mechanisms, which significantly increased the generation of O2•− through the electron transfer pathway over 1O2 production through energy transfer process. The PDPA micelles led to enhanced phototoxicity over the electron-deficient poly(D,L-lactide) control in multiple cancer cell lines under argon-saturated conditions. These data suggest that micelle carriers may not only improve the bioavailability of photosensitizer drugs, but also modulate photophysical properties for improved PDT efficacy. PMID:21888934

  1. Electro-mechanical heat switch for cryogenic applications

    DOEpatents

    van den Berg, Marcel L.; Batteux, Jan D.; Labov, Simon E.

    2003-01-01

    A heat switch includes two symmetric jaws. Each jaw is comprised of a link connected at a translatable joint to a flexible arm. Each arm rotates about a fixed pivot, and has an articulated end including a thermal contact pad connected to a heat sink. The links are joined together at a translatable main joint. To close the heat switch, a closing solenoid is actuated and forces the main joint to an over-center position. This movement rotates the arms about their pivots, respectively, forces each of them into a stressed configuration, and forces the thermal contact pads towards each other and into compressive contact with a cold finger. The closing solenoid is then deactivated. The heat switch remains closed due to a restoring force generated by the stressed configuration of each arm, until actuation of an opening solenoid returns the main joint to its starting open-switch position.

  2. Cross Service Fixed-Wing Cost Estimation

    DTIC Science & Technology

    2016-05-17

    making up the majority of fixed-wing costs , with occasional spikes in some of the other fields like 5.0 Continuing System Improvements. Category 6.0... Costs , a field that can differentiate widely between services and is not a key cost driver when evaluated with the Air Force Systems. The main cost ...TRAC-M-TR-16-021 May 2016 Cross Service Fixed-Wing Cost Estimation TRADOC Analysis Center 700 Dyer Road Monterey, California 93943-0692 This study

  3. Apparatus for fixing latency

    DOEpatents

    Hall, David R [Provo, UT; Bartholomew, David B [Springville, UT; Moon, Justin [Bountiful, UT; Koehler, Roger O [Provo, UT

    2009-09-08

    An apparatus for fixing computational latency within a deterministic region on a network comprises a network interface modem, a high priority module and at least one deterministic peripheral device. The network interface modem is in communication with the network. The high priority module is in communication with the network interface modem. The at least one deterministic peripheral device is connected to the high priority module. The high priority module comprises a packet assembler/disassembler, and hardware for performing at least one operation. Also disclosed is an apparatus for executing at least one instruction on a downhole device within a deterministic region, the apparatus comprising a control device, a downhole network, and a downhole device. The control device is near the surface of a downhole tool string. The downhole network is integrated into the tool string. The downhole device is in communication with the downhole network.

  4. Innovative switching technology

    NASA Astrophysics Data System (ADS)

    Rosen, A.; Stabile, P. J.; Gombar, A. M.; Janton, W. M.; Gilbert, D. B.; Herczfeld, P. R.; Bahasadri, A.

    1991-03-01

    We have developed an all-semiconductor high-power optical switch. Potential uses include both military applications, such as ultra-wide-band impulse radar and high-frequency antenna couplers, and commercial use, such as high-power switching for utility companies. Under this three-year program, we have demonstrated various switching applications from dc to GHz frequencies. The generic switches comprise a 2-D semiconductor laser diode array and Si or GaAs devices. In the Si area (linear switches - no gain) and dc-biased network, a single two-sided PIN device, activated by two 1 kW laser arrays, has yielded a holding voltage of 1.3 kV and conducted 192 A. Similar devices have later yielded a holding voltage of 3.3 kV, demonstrating the capability of switching more than 500 kW with a single two-sided PIN device. The same generic technology was also demonstrated in high-power high-frequency antenna coupler applications as well as in mm-wave (60 GHz) attenuators and phase shifters. PIN devices tested in a RF circuit between 2-30 MHz yielded an isolation value of between 28 and 49 dB in the off-state, and insertion losses as low as 0.1 dB when illuminated with 280 W (peak) optical power at 808 nm. In the area of GaAs, PIN, and bulk devices under this project, we were able to deliver devices for experiments in both opening and closing switches. We have demonstrated a compact, all-semiconductor switch system that has switched up to 8.5 MW into a 38 (omega) load. The system uses a 2-D laser diode array with a peak power of 850 W to rigger a 1.5 cm long GaAs photoconductor into a high-gain combination mode known as 'lock on'. The highest power switch was pulse-charged to 55 kV and delivered 470 A to a 38 (omega) load in 160 ns long pulse. In the area of 2-D laser arrays, a peak power density of 7 kW/cm(exp 2) was achieved.

  5. Fixed Access Network Sharing

    NASA Astrophysics Data System (ADS)

    Cornaglia, Bruno; Young, Gavin; Marchetta, Antonio

    2015-12-01

    Fixed broadband network deployments are moving inexorably to the use of Next Generation Access (NGA) technologies and architectures. These NGA deployments involve building fiber infrastructure increasingly closer to the customer in order to increase the proportion of fiber on the customer's access connection (Fibre-To-The-Home/Building/Door/Cabinet… i.e. FTTx). This increases the speed of services that can be sold and will be increasingly required to meet the demands of new generations of video services as we evolve from HDTV to "Ultra-HD TV" with 4k and 8k lines of video resolution. However, building fiber access networks is a costly endeavor. It requires significant capital in order to cover any significant geographic coverage. Hence many companies are forming partnerships and joint-ventures in order to share the NGA network construction costs. One form of such a partnership involves two companies agreeing to each build to cover a certain geographic area and then "cross-selling" NGA products to each other in order to access customers within their partner's footprint (NGA coverage area). This is tantamount to a bi-lateral wholesale partnership. The concept of Fixed Access Network Sharing (FANS) is to address the possibility of sharing infrastructure with a high degree of flexibility for all network operators involved. By providing greater configuration control over the NGA network infrastructure, the service provider has a greater ability to define the network and hence to define their product capabilities at the active layer. This gives the service provider partners greater product development autonomy plus the ability to differentiate from each other at the active network layer.

  6. Improvements in access to malaria treatment in Tanzania after switch to artemisinin combination therapy and the introduction of accredited drug dispensing outlets - a provider perspective.

    PubMed

    Alba, Sandra; Hetzel, Manuel W; Goodman, Catherine; Dillip, Angel; Liana, Jafari; Mshinda, Hassan; Lengeler, Christian

    2010-06-15

    To improve access to treatment in the private retail sector a new class of outlets known as accredited drug dispensing outlets (ADDO) was created in Tanzania. Tanzania changed its first-line treatment for malaria from sulphadoxine-pyrimethamine (SP) to artemether-lumefantrine (ALu) in 2007. Subsidized ALu was made available in both health facilities and ADDOs. The effect of these interventions on access to malaria treatment was studied in rural Tanzania. The study was carried out in the villages of Kilombero and Ulanga Demographic Surveillance System (DSS) and in Ifakara town. Data collection consisted of: 1) yearly censuses of shops selling drugs; 2) collection of monthly data on availability of anti-malarials in public health facilities; and 3) retail audits to measure anti-malarial sales volumes in all public, mission and private outlets. The data were complemented with DSS population data. Between 2004 and 2008 access to malaria treatment greatly improved and the number of anti-malarial treatment doses dispensed increased by 78%. Particular improvements were observed in the availability (from 0.24 shops per 1,000 people in 2004 to 0.39 in 2008) and accessibility (from 71% of households within 5 km of a shop in 2004 to 87% in 2008) of drug shops. Despite no improvements in affordability this resulted in an increase of the market share from 49% of anti-malarial sales 2005 to 59% in 2008. The change of treatment policy from SP to ALu led to severe stock-outs of SP in health facilities in the months leading up to the introduction of ALu (only 40% months in stock), but these were compensated by the wide availability of SP in shops. After the introduction of ALu stock levels of the drug were relatively high in public health facilities (over 80% months in stock), but the drug could only be found in 30% of drug shops and in no general shops. This resulted in a low overall utilization of the drug (19% of all anti-malarial sales) The public health and private retail

  7. Improvements in access to malaria treatment in Tanzania after switch to artemisinin combination therapy and the introduction of accredited drug dispensing outlets - a provider perspective

    PubMed Central

    2010-01-01

    Background To improve access to treatment in the private retail sector a new class of outlets known as accredited drug dispensing outlets (ADDO) was created in Tanzania. Tanzania changed its first-line treatment for malaria from sulphadoxine-pyrimethamine (SP) to artemether-lumefantrine (ALu) in 2007. Subsidized ALu was made available in both health facilities and ADDOs. The effect of these interventions on access to malaria treatment was studied in rural Tanzania. Methods The study was carried out in the villages of Kilombero and Ulanga Demographic Surveillance System (DSS) and in Ifakara town. Data collection consisted of: 1) yearly censuses of shops selling drugs; 2) collection of monthly data on availability of anti-malarials in public health facilities; and 3) retail audits to measure anti-malarial sales volumes in all public, mission and private outlets. The data were complemented with DSS population data. Results Between 2004 and 2008 access to malaria treatment greatly improved and the number of anti-malarial treatment doses dispensed increased by 78%. Particular improvements were observed in the availability (from 0.24 shops per 1,000 people in 2004 to 0.39 in 2008) and accessibility (from 71% of households within 5 km of a shop in 2004 to 87% in 2008) of drug shops. Despite no improvements in affordability this resulted in an increase of the market share from 49% of anti-malarial sales 2005 to 59% in 2008. The change of treatment policy from SP to ALu led to severe stock-outs of SP in health facilities in the months leading up to the introduction of ALu (only 40% months in stock), but these were compensated by the wide availability of SP in shops. After the introduction of ALu stock levels of the drug were relatively high in public health facilities (over 80% months in stock), but the drug could only be found in 30% of drug shops and in no general shops. This resulted in a low overall utilization of the drug (19% of all anti-malarial sales) Conclusions

  8. A radiation hard vacuum switch

    DOEpatents

    Boettcher, G.E.

    1988-07-19

    A vacuum switch with an isolated trigger probe which is not directly connected to the switching electrodes. The vacuum switch within the plasmatron is triggered by plasma expansion initiated by the trigger probe which travels through an opening to reach the vacuum switch elements. The plasma arc created is directed by the opening to the space between the anode and cathode of the vacuum switch to cause conduction. 3 figs.

  9. Long Life MEM Switch Technology

    DTIC Science & Technology

    2006-05-23

    The first type of MEM switch developed was the miniature switched capacitor. This device is 150-300 times smaller than conventional MEM switches...down and the shunt capacitance to the ground is increased. The mechanical behavior of the MEM capacitor is designed using conventional mechanical...switched capacitors. It proves that by decreasing the size, miniature switched capacitors with Con/ Coff =2.8 for a single bridge and Con/ Coff =1.9 for a 3

  10. Switch to 1.5 grams MMF monotherapy for CNI-related toxicity in liver transplantation is safe and improves renal function, dyslipidemia, and hypertension.

    PubMed

    Orlando, Giuseppe; Baiocchi, Leonardo; Cardillo, Andrea; Iaria, Giuseppe; De Liguori Carino, Nicola; De Liguori, Nicola; De Luca, Linda; Ielpo, Benedetto; Tariciotti, Laura; Angelico, Mario; Tisone, Giuseppe

    2007-01-01

    Although mycophenolate mofetil (MMF) monotherapy has been successfully used in liver transplant recipients suffering from calcineurin-inhibitor (CNI)-related chronic toxicity, still no consensus has been reached on its safety, efficacy and tolerability. We attempted the complete weaning off CNI in 42 individuals presenting chronic renal dysfunction and/or dyslipidemia and/or arterial hypertension and simultaneously introduced 1.5 gm/day MMF. CNI could be completely withdrawn in 41 cases. A total of 32 (75%) patients are currently on improved in 31/36 (89%) cases. Blood levels of cholesterol and triglycerides decreased in 13 of 17 (76%) and 15 of 17 (89%) patients, respectively. Arterial hypertension improved in 4 of 5 (80%) cases. A total of 8 patients showed a single episode of fluctuation of liver function tests during tapering off CNI. This feature was interpreted as an acute rejection (AR), based on the resolution of the clinical setting after escalation of MMF daily dose to 2 gm. A further patient developed a biopsy-proven AR insensitive to MMF adjustment, requiring reinstitution of the CNI dose. No deaths or major toxicity requiring MMF discontinuation occurred. In conclusion, low dose MMF monotherapy is safe, effective, and well tolerated.

  11. Uncertainty quantification in capacitive RF MEMS switches

    NASA Astrophysics Data System (ADS)

    Pax, Benjamin J.

    Development of radio frequency micro electrical-mechanical systems (RF MEMS) has led to novel approaches to implement electrical circuitry. The introduction of capacitive MEMS switches, in particular, has shown promise in low-loss, low-power devices. However, the promise of MEMS switches has not yet been completely realized. RF-MEMS switches are known to fail after only a few months of operation, and nominally similar designs show wide variability in lifetime. Modeling switch operation using nominal or as-designed parameters cannot predict the statistical spread in the number of cycles to failure, and probabilistic methods are necessary. A Bayesian framework for calibration, validation and prediction offers an integrated approach to quantifying the uncertainty in predictions of MEMS switch performance. The objective of this thesis is to use the Bayesian framework to predict the creep-related deflection of the PRISM RF-MEMS switch over several thousand hours of operation. The PRISM switch used in this thesis is the focus of research at Purdue's PRISM center, and is a capacitive contacting RF-MEMS switch. It employs a fixed-fixed nickel membrane which is electrostatically actuated by applying voltage between the membrane and a pull-down electrode. Creep plays a central role in the reliability of this switch. The focus of this thesis is on the creep model, which is calibrated against experimental data measured for a frog-leg varactor fabricated and characterized at Purdue University. Creep plasticity is modeled using plate element theory with electrostatic forces being generated using either parallel plate approximations where appropriate, or solving for the full 3D potential field. For the latter, structure-electrostatics interaction is determined through immersed boundary method. A probabilistic framework using generalized polynomial chaos (gPC) is used to create surrogate models to mitigate the costly full physics simulations, and Bayesian calibration and forward

  12. Metal-to-metal-switches for large currents

    NASA Astrophysics Data System (ADS)

    Schade, Dieter W.; Weise, Thomas H. G. G.; Braunsberger, Ulrich E.; Salge, Juergen G. H.

    1991-01-01

    Existing metal contact switches, originally developed mainly for nuclear fusion research experiments, are reviewed. Their properties are discussed with respect to an application in large capacitor banks for linear mass accelerators. Comparing the different fast metal-to-metal switches developed so far, it can be concluded that nearly all types reviewed can be used as make-switches in capacitor banks for linear mass accelerators. With respect to current carrying capability (up to MA) and voltage (up to some 10 kV) they all meet the requirements for single shots. Compared to gas-discharge switches, their resistance in closed position is one to two orders of magnitude smaller and their inductance is also small. Their switching times and their jitter are sufficient. On the other hand, all switches use solid dielectrics in the form of thin sheets which are inserted between fixed electrodes and which have to be renewed each shot. The switches developed up to now are not suitable to be integrated in large capacitor banks which are split into numerous modules. Furthermore, they are not qualified for high repetition rates.

  13. Development of a prototype T-shaped fast switching device for electron cyclotron current drive systems

    NASA Astrophysics Data System (ADS)

    Sekiguchi, Kenji; Nagashima, Koji; Honzu, Toshihiko; Saigusa, Mikio; Oda, Yasuhisa; Takahashi, Koji; Sakamoto, Keishi

    2016-09-01

    A T-shaped high-power switching device composed of circular corrugated waveguides with three ports and double dielectric disks made of sapphire was proposed as a fast switching device based on a new principle in electron cyclotron current drive systems. This switching device has the advantages of operating at a fixed frequency and being compact. The design of the prototype switch was obtained by numerical simulations using a finite-difference time-domain (FDTD) method. The size of these components was optimized for the frequency band of 170 GHz. Low-power tests were carried out in a cross-shaped model.

  14. Switching power pulse system

    DOEpatents

    Aaland, K.

    1983-08-09

    A switching system for delivering pulses of power from a source to a load using a storage capacitor charged through a rectifier, and maintained charged to a reference voltage level by a transistor switch and voltage comparator. A thyristor is triggered to discharge the storage capacitor through a saturable reactor and fractional turn saturable transformer having a secondary to primary turn ratio N of n:l/n = n[sup 2]. The saturable reactor functions as a soaker'' while the thyristor reaches saturation, and then switches to a low impedance state. The saturable transformer functions as a switching transformer with high impedance while a load coupling capacitor charges, and then switches to a low impedance state to dump the charge of the storage capacitor into the load through the coupling capacitor. The transformer is comprised of a multilayer core having two secondary windings tightly wound and connected in parallel to add their output voltage and reduce output inductance, and a number of single turn windings connected in parallel at nodes for the primary winding, each single turn winding linking a different one of the layers of the multilayer core. The load may be comprised of a resistive beampipe for a linear particle accelerator and capacitance of a pulse forming network. To hold off discharge of the capacitance until it is fully charged, a saturable core is provided around the resistive beampipe to isolate the beampipe from the capacitance until it is fully charged. 5 figs.

  15. Atomic Scale Plasmonic Switch.

    PubMed

    Emboras, Alexandros; Niegemann, Jens; Ma, Ping; Haffner, Christian; Pedersen, Andreas; Luisier, Mathieu; Hafner, Christian; Schimmel, Thomas; Leuthold, Juerg

    2016-01-13

    The atom sets an ultimate scaling limit to Moore's law in the electronics industry. While electronics research already explores atomic scales devices, photonics research still deals with devices at the micrometer scale. Here we demonstrate that photonic scaling, similar to electronics, is only limited by the atom. More precisely, we introduce an electrically controlled plasmonic switch operating at the atomic scale. The switch allows for fast and reproducible switching by means of the relocation of an individual or, at most, a few atoms in a plasmonic cavity. Depending on the location of the atom either of two distinct plasmonic cavity resonance states are supported. Experimental results show reversible digital optical switching with an extinction ratio of 9.2 dB and operation at room temperature up to MHz with femtojoule (fJ) power consumption for a single switch operation. This demonstration of an integrated quantum device allowing to control photons at the atomic level opens intriguing perspectives for a fully integrated and highly scalable chip platform, a platform where optics, electronics, and memory may be controlled at the single-atom level.

  16. Silicon carbide photoconductive switches

    NASA Astrophysics Data System (ADS)

    Saddow, Stephen E.

    1994-09-01

    The optoelectronic properties of p-type 6-H silicon carbide (6H-SiC) have been investigated in an experiment that used lateral and vertical photoconductive (PC) switches. Both photovoltaic and photoconductive effects are reported, which were observed on switches using both geometries and measured at several wavelengths near the 6H-SiC absorption edge. PC techniques were employed to measure the surface and bulk carrier lifetimes of 40 and 200 ns, respectively. The switches displayed a high-speed photovoltaic response to picosecond laser excitations in the UV and visible spectral regions. In particular, efficient subnanosecond optical absorption processes were observed in the visible region. The photovoltage was measured as a function of both laser wavelength (and hence absorption depth) and laser beam position within the switching gap. The switch response to picosecond laser pulses in the UV, violet, green, and red spectral regions was shown to have subnanosecond photovoltaic response times. Finally, since the optical absorption coefficient had not been well established for device-grade 6H-SiC, the optical absorption coefficient near the 6H-SiC bandgap energy (Eg) was also measured, and the bandgap was determined to be approximately 3.1 eV.

  17. Multiple switch actuator

    DOEpatents

    Beyer, Edward T.

    1976-01-06

    The present invention relates to switches and switch actuating devices to be operated for purposes of arming a bomb or other missile as it is dropped or released from an aircraft. The particular bomb or missile in which this invention is applied is one in which there is a plurality of circuits which are to be armed by the closing of switches upon dropping or releasing of the bomb. The operation of the switches to closed position is normally accomplished by means of a pull-out wire; that is, a wire which is withdrawn from the bomb or missile at the time of release of the bomb, one end of the wire being attached to the aircraft. The conditions to be met are that the arming switches must be positively and surely maintained in open position until the bomb is released and the arming action is effected. The action of the pull-out wire in achieving the arming action must be sure and positive with minimum danger of malfunctioning, jamming or binding.

  18. Soft switching active snubbers for DC/DC converters

    SciTech Connect

    Elasser, A.; Torrey, D.A.

    1996-09-01

    A soft-switching active snubber is proposed to reduce the turn-off losses of the insulated gate bipolar transistor (IGBT) in a buck converter. The soft-switching snubber provides zero-voltage switching for the IGBT, thereby reducing its high turn-off losses due to the current tailing. The proposed snubber uses an auxiliary switch to discharge the snubber capacitor. This auxiliary switch also operates at zero-voltage and zero-current switching. The size of the auxiliary switch compared to the main switch makes this snubber a good alternative to the conventional snubber or even to passive low-loss snubbers. The use of the soft-switching active snubber permits the IGBT to operate at high frequencies with an improved RBSOA. In the experimental results reported for a 1 kW, 40 kHz prototype, combined switching/snubbing losses are reduced by 36% through the use of the active snubber compared to a conventional RCD snubber. The use of an active snubber capacitor during turn-off. The generic snubber cell for the buck converter is generalized to support the common nonisolated dc/dc converters (buck, boost, buck-boost, Cuk, sepic, zeta) as well as isolated dc/dc converters (forward, flyback, Cuk, and sepic).

  19. Manufacture of radio frequency micromachined switches with annealing.

    PubMed

    Lin, Cheng-Yang; Dai, Ching-Liang

    2014-01-17

    The fabrication and characterization of a radio frequency (RF) micromachined switch with annealing were presented. The structure of the RF switch consists of a membrane, coplanar waveguide (CPW) lines, and eight springs. The RF switch is manufactured using the complementary metal oxide semiconductor (CMOS) process. The switch requires a post-process to release the membrane and springs. The post-process uses a wet etching to remove the sacrificial silicon dioxide layer, and to obtain the suspended structures of the switch. In order to improve the residual stress of the switch, an annealing process is applied to the switch, and the membrane obtains an excellent flatness. The finite element method (FEM) software CoventorWare is utilized to simulate the stress and displacement of the RF switch. Experimental results show that the RF switch has an insertion loss of 0.9 dB at 35 GHz and an isolation of 21 dB at 39 GHz. The actuation voltage of the switch is 14 V.

  20. GAS DISCHARGE SWITCH EVALUATION FOR RHIC BEAM ABORT KICKER APPLICATION.

    SciTech Connect

    ZHANG,W.; SANDBERG,J.; SHELDRAKE,R.; PIRRIE,C.

    2002-06-30

    A gas discharge switch EEV HX3002 is being evaluated at Brookhaven National Laboratory as a possible candidate of RHIC Beam Abort Kicker modulator main switch. At higher beam energy and higher beam intensity, the switch stability becomes very crucial. The hollow anode thyratron used in the existing system is not rated for long reverse current conduction. The reverse voltage arcing caused thyratron hold-off voltage de-rating has been the main limitation of the system operation. To improve the system reliability, a new type of gas discharge switch has been suggested by Marconi Applied Technology for its reverse conducting capability.

  1. Launched electrons in plasma opening switches

    NASA Astrophysics Data System (ADS)

    Mendel, C. W., Jr.; Rochau, G. E.; Sweeney, M. A.; McDaniel, D. H.; Quintenz, J. P.; Savage, M. E.; Lindman, E. L.; Kindel, J. M.

    Plasma opening switches have provided a means to improve the characteristics of super-power pulse generators. Recent advances involving plasma control with fast and slow magnetic fields have made these switches more versatile, allowing for improved switch uniformity, triggering, and opening current levels that are set by the level of auxiliary fields. Such switches necessarily involve breaks in the translational symmetry of the transmission line geometry and therefore affect the electron flow characteristics of the line. These symmetry breaks are the result of high electric field regions caused by plasma conductors remaining in the transmission line, ion beams crossing the line, or auxilliary magnetic field regions. Symmetry breaks cause the canonical momentum of the electrons to change, thereby moving them away from the cathode. Additional electrons are pulled from the cathode into the magnetically insulated flow, resulting in an excess of electron flow over that expected for the voltage and line current downstream of the switch. These electrons are called launched electrons. Unless they are recaptured at the cathode or else are fed into the load and used beneficially, they cause a large power loss downstream. Examples are shown of SuperMite and PBFA II data showing these losses, the tools used to study them are explained, and the mechanisms employed to mitigate the problem are discussed. The losses will be reduced primarily by reducing the amount of launched electron flow.

  2. Sub-hundred nanosecond electrostatic actuated RF MEMS switched capacitors

    NASA Astrophysics Data System (ADS)

    Verger, A.; Pothier, A.; Guines, C.; Crunteanu, A.; Blondy, P.; Orlianges, J.-C.; Dhennin, J.; Broue, A.; Courtade, F.; Vendier, O.

    2010-06-01

    This paper presents a new mechanical architecture for RF MEMS components that are able to achieve reconfiguration faster than conventional MEMS switches. For most MEMS switches, the electrical switching speed is generally limited to a few microseconds, inherently restricted by the delay required to mechanically move their mobile membrane up and down. By using a proper mechanical design and the structural material fabrication process, this paper will show miniature bridges that are able to exhibit mechanical resonance frequencies over 10 MHz range to be compared to the few tens of kHz for conventional RF MEMS switches. As a result, the switching speed of these miniature components is greatly improved and reaches 50 to 100 ns. Such performance has been achieved using composite micro-beams based on the multilayer material assembly of alumina/aluminum/alumina. To our knowledge, this is the fastest switching speed reported for RF MEMS components so far.

  3. Recent advances in column switching sample preparation in bioanalysis.

    PubMed

    Kataoka, Hiroyuki; Saito, Keita

    2012-04-01

    Column switching techniques, using two or more stationary phase columns, are useful for trace enrichment and online automated sample preparation. Target fractions from the first column are transferred online to a second column with different properties for further separation. Column switching techniques can be used to determine the analytes in a complex matrix by direct sample injection or by simple sample treatment. Online column switching sample preparation is usually performed in combination with HPLC or capillary electrophoresis. SPE or turbulent flow chromatography using a cartridge column and in-tube solid-phase microextraction using a capillary column have been developed for convenient column switching sample preparation. Furthermore, various micro-/nano-sample preparation devices using new polymer-coating materials have been developed to improve extraction efficiency. This review describes current developments and future trends in novel column switching sample preparation in bioanalysis, focusing on innovative column switching techniques using new extraction devices and materials.

  4. Photoconductive switch enhancements for use in Blumlein pulse generators

    NASA Astrophysics Data System (ADS)

    Davanloo, F.; Park, H.; Collins, C. B.; Agee, F. J.

    1999-06-01

    Stacked Blumlein pulse generators developed at the University of Texas at Dallas have produced high-power waveforms with risetimes and repetition rates in the range of 0.2-50 ns and 1-300 Hz, respectively, using a conventional thyratron, spark gap or photoconductive switch. Adaptation of the design has enabled the stacked Blumleins to produce 80 MW, nanosecond pulses with risetimes better than 200 ps into nominally matched loads. The device has a compact line geometry and is commutated by a single GaAs photoconductive switch triggered by a low power laser diode array. Our current investigations involve the switch characteristics that affect the broadening of the current channels in the avalanche, pre-avalanche seedings, the switch lifetime and the durability. This report presents the progress toward improving the GaAs switch operation and lifetime in stacked Blumlein pulsers. Advanced switch treatments including diamond film overcoating are implemented and discussed.

  5. Microfabricated triggered vacuum switch

    DOEpatents

    Roesler, Alexander W.; Schare, Joshua M.; Bunch, Kyle

    2010-05-11

    A microfabricated vacuum switch is disclosed which includes a substrate upon which an anode, cathode and trigger electrode are located. A cover is sealed over the substrate under vacuum to complete the vacuum switch. In some embodiments of the present invention, a metal cover can be used in place of the trigger electrode on the substrate. Materials used for the vacuum switch are compatible with high vacuum, relatively high temperature processing. These materials include molybdenum, niobium, copper, tungsten, aluminum and alloys thereof for the anode and cathode. Carbon in the form of graphitic carbon, a diamond-like material, or carbon nanotubes can be used in the trigger electrode. Channels can be optionally formed in the substrate to mitigate against surface breakdown.

  6. Optical computer switching network

    NASA Technical Reports Server (NTRS)

    Clymer, B.; Collins, S. A., Jr.

    1985-01-01

    The design for an optical switching system for minicomputers that uses an optical spatial light modulator such as a Hughes liquid crystal light valve is presented. The switching system is designed to connect 80 minicomputers coupled to the switching system by optical fibers. The system has two major parts: the connection system that connects the data lines by which the computers communicate via a two-dimensional optical matrix array and the control system that controls which computers are connected. The basic system, the matrix-based connecting system, and some of the optical components to be used are described. Finally, the details of the control system are given and illustrated with a discussion of timing.

  7. Switching power supply

    DOEpatents

    Mihalka, A.M.

    1984-06-05

    The invention is a repratable capacitor charging, switching power supply. A ferrite transformer steps up a dc input. The transformer primary is in a full bridge configuration utilizing power MOSFETs as the bridge switches. The transformer secondary is fed into a high voltage, full wave rectifier whose output is connected directly to the energy storage capacitor. The transformer is designed to provide adequate leakage inductance to limit capacitor current. The MOSFETs are switched to the variable frequency from 20 to 50 kHz to charge a capacitor from 0.6 kV. The peak current in a transformer primary and secondary is controlled by increasing the pulse width as the capacitor charges. A digital ripple counter counts pulses and after a preselected desired number is reached an up-counter is clocked.

  8. SWITCH user's manual

    NASA Technical Reports Server (NTRS)

    1987-01-01

    The planning program, SWITCH, and its surrounding changed-goal-replanning program, Runaround, are described. The evolution of SWITCH and Runaround from an earlier planner, DEVISER, is recounted. SWITCH's plan representation, and its process of building a plan by backward chaining with strict chronological backtracking, are described. A guide for writing knowledge base files is provided, as are narrative guides for installing the program, running it, and interacting with it while it is running. Some utility functions are documented. For the sake of completeness, a narrative guide to the experimental discrepancy-replanning feature is provided. Appendices contain knowledge base files for a blocksworld domain, and a DRIBBLE file illustrating the output from, and user interaction with, the program in that domain.

  9. Optical Computer Switching Network

    NASA Astrophysics Data System (ADS)

    Clymer, B.; Collins, S. A., Jr.

    1985-02-01

    In this paper we present the design for an optical switching system for minicomputers that uses an optical spatial light modulator such as a Hughes liquid crystal light valve. The switching system is designed to connect 80 minicomputers coupled to the switching system by optical fibers. The system has two major parts: the connection system that connects the data lines by which the computers communicate via a two-dimensional optical matrix array and the control system that controls which computers are connected. We first present the basic system, then describe the matrix-based connecting system and review some of the optical components to be used. Finally, the details of the control system are given and illustrated with a discussion of timing.

  10. Optical computer switching network

    NASA Astrophysics Data System (ADS)

    Clymer, B.; Collins, S. A., Jr.

    1985-02-01

    The design for an optical switching system for minicomputers that uses an optical spatial light modulator such as a Hughes liquid crystal light valve is presented. The switching system is designed to connect 80 minicomputers coupled to the switching system by optical fibers. The system has two major parts: the connection system that connects the data lines by which the computers communicate via a two-dimensional optical matrix array and the control system that controls which computers are connected. The basic system, the matrix-based connecting system, and some of the optical components to be used are described. Finally, the details of the control system are given and illustrated with a discussion of timing.

  11. Optical computer switching network

    NASA Technical Reports Server (NTRS)

    Clymer, B.; Collins, S. A., Jr.

    1985-01-01

    The design for an optical switching system for minicomputers that uses an optical spatial light modulator such as a Hughes liquid crystal light valve is presented. The switching system is designed to connect 80 minicomputers coupled to the switching system by optical fibers. The system has two major parts: the connection system that connects the data lines by which the computers communicate via a two-dimensional optical matrix array and the control system that controls which computers are connected. The basic system, the matrix-based connecting system, and some of the optical components to be used are described. Finally, the details of the control system are given and illustrated with a discussion of timing.

  12. FAST ACTING CURRENT SWITCH

    DOEpatents

    Batzer, T.H.; Cummings, D.B.; Ryan, J.F.

    1962-05-22

    A high-current, fast-acting switch is designed for utilization as a crowbar switch in a high-current circuit such as used to generate the magnetic confinement field of a plasma-confining and heat device, e.g., Pyrotron. The device particularly comprises a cylindrical housing containing two stationary, cylindrical contacts between which a movable contact is bridged to close the switch. The movable contact is actuated by a differential-pressure, airdriven piston assembly also within the housing. To absorb the acceleration (and the shock imparted to the device by the rapidly driven, movable contact), an adjustable air buffer assembly is provided, integrally connected to the movable contact and piston assembly. Various safety locks and circuit-synchronizing means are also provided to permit proper cooperation of the invention and the high-current circuit in which it is installed. (AEC)

  13. Failure to improve door-to-needle time by switching to emergency physician-initiated thrombolysis for ST elevation myocardial infarction

    PubMed Central

    Loch, Alexander; Lwin, Tint; Zakaria, Idzwan Mohd; Abidin, Imran Zainal; Wan Ahmad, Wan Azman; Hautmann, Oliver

    2013-01-01

    Introduction Achieving target door–needle times for ST elevation myocardial infarction remains challenging. Data on emergency department (ED) doctor-led thrombolysis in developing countries and factors causing delay are limited. Objectives To assess the effect on door–needle times by transferring responsibility for thrombolysis to the ED doctors and to identify predictors of prolonged door–needle times. Methodology Data on medical on-call team-led thrombolysis at a tertiary Asian hospital were prospectively collected from May 2007 to Aug 2008 (1st study period). In September 2008, ED doctors were empowered to perform thrombolysis. The practice change was accompanied by new guidelines, tick chart implementation, and training sessions. Data were then consecutively collected from September 2008 to May 2009 (2nd study period). Door-to-needle times for the 1st and 2nd study periods were compared. All cases were analysed for factors of delay by multiple logistic regression. Results 297 patients were thrombolysed, 169 by the medical on-call team during the 1st study period and 128 by the ED doctors during the 2nd study period. Median door–needle times were 54 and 48 min, respectively (p=0.76). Significant delays were predicted by ‘incorrect initial ECG interpretation’ (adjusted OR (aOR) 14.3), ‘inappropriate triage’ (aOR 10.4) and ‘multiple referrals’ (aOR 5.9). No cases of inappropriate thrombolysis were recorded. Conclusions Transfer of responsibility for thrombolysis to the ED doctors did not improve door–needle times despite measures introduced to facilitate this change. Key causative factors for this failure were identified. PMID:23524989

  14. Failure to improve door-to-needle time by switching to emergency physician-initiated thrombolysis for ST elevation myocardial infarction.

    PubMed

    Loch, Alexander; Lwin, Tint; Zakaria, Idzwan Mohd; Abidin, Imran Zainal; Wan Ahmad, Wan Azman; Hautmann, Oliver

    2013-06-01

    Achieving target door-needle times for ST elevation myocardial infarction remains challenging. Data on emergency department (ED) doctor-led thrombolysis in developing countries and factors causing delay are limited. To assess the effect on door-needle times by transferring responsibility for thrombolysis to the ED doctors and to identify predictors of prolonged door-needle times. Data on medical on-call team-led thrombolysis at a tertiary Asian hospital were prospectively collected from May 2007 to Aug 2008 (1st study period). In September 2008, ED doctors were empowered to perform thrombolysis. The practice change was accompanied by new guidelines, tick chart implementation, and training sessions. Data were then consecutively collected from September 2008 to May 2009 (2nd study period). Door-to-needle times for the 1st and 2nd study periods were compared. All cases were analysed for factors of delay by multiple logistic regression. 297 patients were thrombolysed, 169 by the medical on-call team during the 1st study period and 128 by the ED doctors during the 2nd study period. Median door-needle times were 54 and 48 min, respectively (p=0.76). Significant delays were predicted by 'incorrect initial ECG interpretation' (adjusted OR (aOR) 14.3), 'inappropriate triage' (aOR 10.4) and 'multiple referrals' (aOR 5.9). No cases of inappropriate thrombolysis were recorded. Transfer of responsibility for thrombolysis to the ED doctors did not improve door-needle times despite measures introduced to facilitate this change. Key causative factors for this failure were identified.

  15. Fixed Dosing of Monoclonal Antibodies in Oncology.

    PubMed

    Hendrikx, Jeroen J M A; Haanen, John B A G; Voest, Emile E; Schellens, Jan H M; Huitema, Alwin D R; Beijnen, Jos H

    2017-07-28

    Most monoclonal antibodies in oncology are administered in body-size-based dosing schedules. This is believed to correct for variability in both drug distribution and elimination between patients. However, monoclonal antibodies typically distribute to the blood plasma and extracellular fluids only, which increase less than proportionally with the increase in body weight. Elimination takes place via proteolytic catabolism, a nonspecific immunoglobulin G elimination pathway, and intracellular degradation after binding to the target. The latter is the primary route of elimination and is related to target expression levels rather than body size. Taken together, the minor effects of body size on distribution and elimination of monoclonal antibodies and their usually wide therapeutic window do not support body-size-based dosing. We evaluated effects of body weight on volume of distribution and clearance of monoclonal antibodies in oncology and show that a fixed dose for most of these drugs is justified based on pharmacokinetics. A survey of the savings after fixed dosing of monoclonal antibodies at our hospital showed that fixed dosing can reduce costs of health care, especially when pooling of preparations is not possible (which is often the case in smaller hospitals). In conclusion, based on pharmacokinetic parameters of monoclonal antibodies, there is a rationale for fixed dosing of these drugs in oncology. Therefore, we believe that fixed dosing is justified and can improve efficiency of the compounding. Moreover, drug spillage can be reduced and medication errors may become less likely. The currently available knowledge of elimination of monoclonal antibodies combined with the publicly available data from clinical trials and extensive population pharmacokinetic (PopPK) modeling justifies fixed dosing. Interpatient variation in exposure is comparable after body weight and fixed dosing and most monoclonal antibodies show relatively flat dose-response relationships

  16. Simple Robust Fixed Lag Smoothing

    DTIC Science & Technology

    1988-12-02

    SIMPLE ROBUST FIXED LAG SMOOTHING by ~N. D. Le R.D. Martin 4 TECHNICAL RlEPORT No. 149 December 1988 Department of Statistics, GN-22 Accesion For...frLsD1ist Special A- Z Simple Robust Fixed Lag Smoothing With Application To Radar Glint Noise * N. D. Le R. D. Martin Department of Statistics, GN...smoothers. The emphasis here is on fixed-lag smoothing , as opposed to the use of existing robust fixed interval smoothers (e.g., as in Martin, 1979

  17. SHOCKPROOF MAGNETIC REED SWITCH

    DOEpatents

    Medal, E.

    1962-03-13

    A shockproof magnetic reed switch is described which comprises essentially a plurality of pairs of reed contacts of magnetic, electrical conducting material which are arranged generally in circumferential spaced relationship. At least two of the pairs are disposed to operate at a predetermined angle with respect to each other, and the contacts are wired in the circuit, so that the continuity, or discontinuity, of the circuit is not affected by a shock imposed on the switch. The contacts are hermetically sealed within an outer tubular jacket. (AEC)

  18. Thermionic gas switch

    DOEpatents

    Hatch, George L.; Brummond, William A.; Barrus, Donald M.

    1986-01-01

    A temperature responsive thermionic gas switch having folded electron emitting surfaces. An ionizable gas is located between the emitter and an interior surface of a collector, coaxial with the emitter. In response to the temperature exceeding a predetermined level, sufficient electrons are derived from the emitter to cause the gas in the gap between the emitter and collector to become ionized, whereby a very large increase in current in the gap occurs. Due to the folded emitter surface area of the switch, increasing the "on/off" current ratio and adjusting the "on" current capacity is accomplished.

  19. Organometallic spintronics: dicobaltocene switch.

    PubMed

    Liu, Rui; Ke, San-Huang; Baranger, Harold U; Yang, Weitao

    2005-10-01

    A single-molecule spintronic switch and spin valve using two cobaltocene moieties is proposed. Spin-dependent transport through a lead-molecule-lead junction has been calculated using first-principles density functional and nonequilibrium Green function methods. We find that the antiparallel (singlet) configuration of the cobaltocene spins blocks electron transport near the Fermi energy, while the spin parallel (triplet) configuration enables much higher current. The energy difierence between the antiparallel and parallel states depends on the insulating spacer separating the two cobaltocenes, allowing switching through the application of a moderate magnetic field.

  20. Nanocoating with titanium reduces iC3b- and granulocyte-activating immune response against glutaraldehyde-fixed bovine pericardium: a new technique to improve biologic heart valve prosthesis durability?

    PubMed

    Guldner, Norbert W; Bastian, Fabienne; Weigel, Günther; Zimmermann, Hanngörg; Maleika, Markus; Scharfschwerdt, Michael; Rohde, Daniel; Sievers, Hans-Hinrich

    2012-05-01

    An IgG and granulocyte-activating immune response with secondary dystrophic calcification might be the reason glutaraldehyde (GA)-fixed xenograft valves fail, especially in young patients, who are more immunocompetent than the elderly. Titanium nanocoating on GA-fixed bovine pericardium was tested for its ability to prevent major immunoreactions. The immune activity of platelets from GA-fixed bovine pericardium with different treatment procedures was evaluated using the blood from 5 human donors: group I (n = 5), GA fixed as the control; group 2 (n = 5), detoxified with 10% citric acid; group 3 (n = 5), 10% citric acid, aldehyde-dehydrogenase, and a physical plasma treatment; and group 4 (n = 5), treated the same as group 3, but with an additional titanium coat 30 nm in thickness. Titanium deposition was visualized using scanning electron microscopy. IgG deposits (iC3b) were shown by immunostaining and documented as colored pixels (red). The pixels were evaluated electronically. Attracted granulocytes (polymorphonuclear leukocytes) were counted in front of the titanium-coated surface. IC3b deposits and polymorphonuclear leukocytes within control group 1 were defined as 100%; in group 2, iC3b was 149% ± 34% and polymorphonuclear leukocytes were 89%, in group 3, IC3b was 102% ± 24% and polymorphonuclear leukocytes were 47%; and in group 4, IC3b had decreased to 38.49% ± 21% (P < .05) and polymorphonuclear leukocyte activation had decreased to 6.3% (P ≤ .01). Titanium coating significantly reduced the iC3b and granulocyte activating immune response of GA-fixed pericardium. Therefore, it might prevent relevant immunorejection and increase the durability of GA-fixed bioprosthetic heart valves. Copyright © 2012 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

  1. Optically initiated silicon carbide high voltage switch

    SciTech Connect

    Caporaso, George J; Sampayan, Stephen E; Sullivan, James S; Sanders,; David, M

    2011-02-22

    An improved photoconductive switch having a SiC or other wide band gap substrate material, such as GaAs and field-grading liners composed of preferably SiN formed on the substrate adjacent the electrode perimeters or adjacent the substrate perimeters for grading the electric fields.

  2. Main electrical switch banks, plant switch house, looking to the ...

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

    Main electrical switch banks, plant switch house, looking to the North - Bureau of Mines Metallurgical Research Laboratory, Original Building, Date Street north of U.S. Highway 93, Boulder City, Clark County, NV

  3. Hybrid solid state switch replaces motor- driven power switch

    NASA Technical Reports Server (NTRS)

    Booth, R. A.; Schloss, A. I.

    1967-01-01

    Hybrid solid state switch replaces existing motor-driven power switches used on spacecraft. It uses a transistor circuit to limit the open circuit voltage and allow small relay contacts to handle high transient currents at reasonable cycle life.

  4. 41. INTERIOR VIEW, GREEN SWITCH TOWER, COS COB, SHOWING SWITCH ...

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

    41. INTERIOR VIEW, GREEN SWITCH TOWER, COS COB, SHOWING SWITCH LEVER ASSEMBLAGE AND DISPLAY BOARD - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  5. 35. END VIEW, INTERIOR, SHOWING SWITCHING LEVERS, BERK SWITCH TOWER, ...

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

    35. END VIEW, INTERIOR, SHOWING SWITCHING LEVERS, BERK SWITCH TOWER, SOUTH NORWALK - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  6. 36. INTERIOR VIEW, BERK SWITCH TOWER, SOUTH NORWALK, SHOWING SWITCHING ...

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

    36. INTERIOR VIEW, BERK SWITCH TOWER, SOUTH NORWALK, SHOWING SWITCHING LEVERS FROM OPERATOR'S POSITION - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  7. 43. OBLIQUE VIEW, GREEN SWITCH TOWER, COS COB, SHOWING SWITCH ...

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

    43. OBLIQUE VIEW, GREEN SWITCH TOWER, COS COB, SHOWING SWITCH LEVER ASSEMBLAGE AND DISPLAY BOARD - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  8. Customizable Gas-Gap Heat Switch

    NASA Astrophysics Data System (ADS)

    Martins, D.; Catarino, I.; Schroder, U.; Ricardo, J.; Patricio, R.; Duband, L.; Bonfait, G.

    2010-04-01

    The so-called gas gap heat switch, in which the pressure is managed by a coupled small cryopump having no moving parts, is known to be a very reliable and simple heat switch. Mechanical design improvements can lead to optimized ON or OFF characteristics of a gas-gap heat switch. Their ON conductance characteristics are mainly determined by the gas properties and the gap geometry. However, their operational temperature range is limited by the gas-sorbent pair adsorption characteristics. Traditionally the gas chosen is helium, since it is the best conductive one below 100 K, and the sorbent used is activated charcoal. Such a switch is limited to be used at cold end temperatures below ˜15 K. In order to obtain a customizable device working at the whole range below 100 K, a gas gap heat switch was studied and extensively characterized. Hydrogen, Neon and Nitrogen were used as conducting gas, under different sorption conditions. A thermal model was built in order to determine the ON and OFF conductances over each entire temperature range. This work presents the operational temperature windows established for each gas, depending on the amount of gas used. The experimental results and those predicted by the model are in quite good agreement. Such windows allow the tuning of a gas gap heat switch to be used under particular circumstances. The adsorption properties of various types of activated charcoals and their consequences on the operational temperature windows are being studied in order to allow a still larger customization of such heat switches.

  9. Lifetime characteristics of ohmic MEMS switches

    NASA Astrophysics Data System (ADS)

    Maciel, John; Majumder, Sumit; Morrison, Richard; Lampen, James

    2003-12-01

    In the future, MEMS switches will be important building blocks for designing phase shifters, smart antennas, cell phones and switched filters for military and commercial markets, to name a few. Low power consumption, large ratio of off-impedance to on-impedance and the ability to be integrated with other electronics makes MEMS switches an attractive alternative to other mechanical and solid-state switches. Radant MEMS has developed an electrostatically actuated broadband ohmic microswitch that has applications from DC through the microwave region. The microswitch is a 3-terminal device based on a cantilever beam and is fabricated using an all-metal, surface micromachining process. It operates in a hermetic environment obtained through a wafer-bonding process. We have developed PC-based test stations to cycle switches and measure lifetime under DC and RF loads. Best-case lifetimes of 1011 cycles have been achieved in T0-8 cans (a precursor to our wafer level cap) while greater than 1010 cycles have been achieved in the wafer level package. Several switches from different lots have been operated to 1010 cycles. Current typical lifetime exceeds 2 billion cycles and is limited by contact stiction resulting in stuck-closed failures. Stuck-closed failures can be intermittent with a large number of switches continuing to operate with occasional sticks beyond several billion cycles. To eliminate contact stiction, we need to better control the ambient gas composition in the die cavity. We expect lifetime to improve as we continue to develop and optimize the wafer capping process. We present DC and RF lifetime data under varying conditions.

  10. Photonic MEMS switch applications

    NASA Astrophysics Data System (ADS)

    Husain, Anis

    2001-07-01

    As carriers and service providers continue their quest for profitable network solutions, they have shifted their focus from raw bandwidth to rapid provisioning, delivery and management of revenue generating services. Inherently transparent to data rate the transmission wavelength and data format, MEMS add scalability, reliability, low power and compact size providing flexible solutions to the management and/or fiber channels in long haul, metro, and access networks. MEMS based photonic switches have gone from the lab to commercial availability and are now currently in carrier trials and volume production. 2D MEMS switches offer low up-front deployment costs while remaining scalable to large arrays. They allow for transparent, native protocol transmission. 2D switches enable rapid service turn-up and management for many existing and emerging revenue rich services such as storage connectivity, optical Ethernet, wavelength leasing and optical VPN. As the network services evolve, the larger 3D MEMS switches, which provide greater scalability and flexibility, will become economically viable to serve the ever-increasing needs.

  11. Kiowa Creek Switching Station

    SciTech Connect

    Not Available

    1990-03-01

    The Western Area Power Administration (Western) proposes to construct, operate, and maintain a new Kiowa Creek Switching Station near Orchard in Morgan County, Colorado. Kiowa Creek Switching Station would consist of a fenced area of approximately 300 by 300 feet and contain various electrical equipment typical for a switching station. As part of this new construction, approximately one mile of an existing 115-kilovolt (kV) transmission line will be removed and replaced with a double circuit overhead line. The project will also include a short (one-third mile) realignment of an existing line to permit connection with the new switching station. In accordance with the Council on Environmental Quality (CEQ) regulations for implementing the procedural provisions of the National Environmental Policy Act of 1969 (NEPA), 40 CFR Parts 1500--1508, the Department of Energy (DOE) has determined that an environmental impact statement (EIS) is not required for the proposed project. This determination is based on the information contained in this environmental assessment (EA) prepared by Western. The EA identifies and evaluates the environmental and socioeconomic effects of the proposed action, and concludes that the advance impacts on the human environment resulting from the proposed project would not be significant. 8 refs., 3 figs., 1 tab.

  12. Multipath star switch controller

    NASA Technical Reports Server (NTRS)

    Anderson, T. O.

    1980-01-01

    Device concept permits parallel computers to scan several commonnetwork-connected data stations at maximum rate. Sequencers leap-frog to bypass ports already being serviced by another computer. Two-path system for 16-port star switch controller is cost effective if added bandwidth or increased reliability is desired. Triple-path system would be cost effective for 32-port controller.

  13. Waveguide switch protector

    NASA Technical Reports Server (NTRS)

    Kolbly, R. B.

    1972-01-01

    Device for detecting excessive operation of electric motors used to drive waveguide switches is described. Purpose of device is to prevent burnout of electric motor in event of waveguide stoppage at some point other than extreme limits of travel. Operation of equipment, components used to sense motor performance, and schematic diagram are included.

  14. Gas injected vacuum switch

    DOEpatents

    Hardin, K. Dan

    1977-01-01

    The disclosure relates to a gas injected vacuum switch comprising a housing having an interior chamber, a conduit for evacuating the interior chamber, within the chamber an anode and a cathode spaced from the anode, and a detonator for injecting electrically conductive gas into the chamber between the anode and the cathode to provide a current path therebetween.

  15. Silicon Carbide Photoconductive Switches

    DTIC Science & Technology

    1994-09-01

    The optoelectronic properties of p-type 6-H silicon carbide (6H-SiC) have been investigated in an experiment that used lateral and vertical...and the bandgap was determined to be approximately 3.1 eV. 6H-SiC, Photoconductive, Photovoltaic, Absorption coefficient, Switch, Silicon carbide

  16. An integrated circuit switch

    NASA Technical Reports Server (NTRS)

    Bonin, E. L.

    1969-01-01

    Multi-chip integrated circuit switch consists of a GaAs photon-emitting diode in close proximity with S1 phototransistor. A high current gain is obtained when the transistor has a high forward common-emitter current gain.

  17. Molecular Rotors as Switches

    PubMed Central

    Xue, Mei; Wang, Kang L.

    2012-01-01

    The use of a functional molecular unit acting as a state variable provides an attractive alternative for the next generations of nanoscale electronics. It may help overcome the limits of conventional MOSFETd due to their potential scalability, low-cost, low variability, and highly integratable characteristics as well as the capability to exploit bottom-up self-assembly processes. This bottom-up construction and the operation of nanoscale machines/devices, in which the molecular motion can be controlled to perform functions, have been studied for their functionalities. Being triggered by external stimuli such as light, electricity or chemical reagents, these devices have shown various functions including those of diodes, rectifiers, memories, resonant tunnel junctions and single settable molecular switches that can be electronically configured for logic gates. Molecule-specific electronic switching has also been reported for several of these device structures, including nanopores containing oligo(phenylene ethynylene) monolayers, and planar junctions incorporating rotaxane and catenane monolayers for the construction and operation of complex molecular machines. A specific electrically driven surface mounted molecular rotor is described in detail in this review. The rotor is comprised of a monolayer of redox-active ligated copper compounds sandwiched between a gold electrode and a highly-doped P+ Si. This electrically driven sandwich-type monolayer molecular rotor device showed an on/off ratio of approximately 104, a read window of about 2.5 V, and a retention time of greater than 104 s. The rotation speed of this type of molecular rotor has been reported to be in the picosecond timescale, which provides a potential of high switching speed applications. Current-voltage spectroscopy (I-V) revealed a temperature-dependent negative differential resistance (NDR) associated with the device. The analysis of the device I–V characteristics suggests the source of the

  18. Exhaust Fan Temperature Switch

    SciTech Connect

    Ball, G.S.; /Fermilab

    1989-05-11

    The 13000 cfm 'emergency' vent fan must be protected from over cooling which would result in a mechanical failure. Over cooling could result from a catastrophic cryogen release from the cryostat(s) or Argon Storage Dewar. In order to protect the fan, a VPT has been calibrated for -31 C to open a switch which sends a signal to allow warm gas to enter the sump by means of a motor controlled louver installed at 'sidewalk level' in the ductwork between the assembly hall and the Argon Dewar Enclosure. The bulb of the VPT is enclosed in a thermal well and will be placed in the gas stream directly above the fan. The switching unit will be mounted nearby on the wall in order to isolate it from vibrational effects. Should the fan be activated due to a cryogen release, it should not experience any problems when operating above -40 C. The switch was set and checked in a saturated calcium chloride solution cooled to -31 C by running cold gaseous Nitrogen through a copper tube coiled in a dewar. Switching temperature was measured by a thermocouple tied to the VPT bulb. The thermocouple was checked in LN2, in an ice water bath, and against an ordinary thermometer (which was assumed to be accurate to plus or minus 0.3 C) at room temperature. The results are shown below in 'Table 1' By interpolation of the data, thermocouple error at -31.0 C was found to be 0.43 C on the warm side. Since this error was small, it was ignored. 'Table 2' shows the results of the tests. Ten readings were taken with the switch wired in the 'normally open' mode. This results in a signal at room temperature. The worst deviation was 2.5 C. Three readings were then taken from the 'normally closed' wiring arrangement (the way it will be wired for installation). The greatest deviation was 1.2 C. The next day, the switch was checked five times wired in the 'normally open' configuration. The greatest error was 1.1 C. A graph has been prepared showing the switching and resetting temperatures. The errors these

  19. Fixed points of quantum gravity.

    PubMed

    Litim, Daniel F

    2004-05-21

    Euclidean quantum gravity is studied with renormalization group methods. Analytical results for a nontrivial ultraviolet fixed point are found for arbitrary dimensions and gauge fixing parameters in the Einstein-Hilbert truncation. Implications for quantum gravity in four dimensions are discussed.

  20. Heat-transfer thermal switch

    NASA Technical Reports Server (NTRS)

    Friedell, M. V.; Anderson, A. J.

    1974-01-01

    Thermal switch maintains temperature of planetary lander, within definite range, by transferring heat. Switch produces relatively large stroke and force, uses minimum electrical power, is lightweight, is vapor pressure actuated, and withstands sterilization temperatures without damage.

  1. Automatic thermal switch. [spacecraft applications

    NASA Technical Reports Server (NTRS)

    Cunningham, J. W.; Wing, L. D. (Inventor)

    1983-01-01

    An automatic thermal switch to control heat flow includes two thermally conductive plates and a thermally conductive switch saddle pivotally mounted to the first plate. A flexible heat carrier is connected between the switch saddle and the second plate. A phase-change power unit, including a piston coupled to the switch saddle, is in thermal contact with the first thermally conductive plate. A biasing element biases the switch saddle in a predetermined position with respect to the first plate. When the phase-change power unit is actuated by an increase in heat transmitted through the first place, the piston extends and causes the switch saddle to pivot, thereby varying the thermal conduction between the two plates through the switch saddle and flexible heat carrier. The biasing element, switch saddle, and piston can be arranged to provide either a normally closed or normally opened thermally conductive path between the two plates.

  2. Switching power pulse system

    DOEpatents

    Aaland, Kristian

    1983-01-01

    A switching system for delivering pulses of power from a source (10) to a load (20) using a storage capacitor (C3) charged through a rectifier (D1, D2), and maintained charged to a reference voltage level by a transistor switch (Q1) and voltage comparator (12). A thyristor (22) is triggered to discharge the storage capacitor through a saturable reactor (18) and fractional turn saturable transformer (16) having a secondary to primary turn ratio N of n:l/n=n.sup.2. The saturable reactor (18) functions as a "soaker" while the thyristor reaches saturation, and then switches to a low impedance state. The saturable transformer functions as a switching transformer with high impedance while a load coupling capacitor (C4) charges, and then switches to a low impedance state to dump the charge of the storage capacitor (C3) into the load through the coupling capacitor (C4). The transformer is comprised of a multilayer core (26) having two secondary windings (28, 30) tightly wound and connected in parallel to add their output voltage and reduce output inductance, and a number of single turn windings connected in parallel at nodes (32, 34) for the primary winding, each single turn winding linking a different one of the layers of the multilayer core. The load may be comprised of a resistive beampipe (40) for a linear particle accelerator and capacitance of a pulse forming network (42). To hold off discharge of the capacitance until it is fully charged, a saturable core (44) is provided around the resistive beampipe (40) to isolate the beampipe from the capacitance (42) until it is fully charged.

  3. Fixing Maintenance Productivity.

    ERIC Educational Resources Information Center

    Fickes, Michael

    2003-01-01

    Describes how one university's facility managers use Nextel communications technology in conjunction with a Famis Software maintenance management system to improve the productivity of its maintenance technicians. The system uses a wireless Internet connection to automate the flow of work order information to and from technicians. The key to these…

  4. Fixing Teacher Professional Development

    ERIC Educational Resources Information Center

    Hill, Heather C.

    2009-01-01

    The professional development "system" for teachers is, by all accounts, broken. Despite evidence that specific programs can improve teacher knowledge and practice and student outcomes, these programs seldom reach real teachers on a large scale. Typically, reformers address such perceptions of failure by discovering and celebrating new formats and…

  5. Fixing Maintenance Productivity.

    ERIC Educational Resources Information Center

    Fickes, Michael

    2003-01-01

    Describes how one university's facility managers use Nextel communications technology in conjunction with a Famis Software maintenance management system to improve the productivity of its maintenance technicians. The system uses a wireless Internet connection to automate the flow of work order information to and from technicians. The key to these…

  6. Fixing Teacher Professional Development

    ERIC Educational Resources Information Center

    Hill, Heather C.

    2009-01-01

    The professional development "system" for teachers is, by all accounts, broken. Despite evidence that specific programs can improve teacher knowledge and practice and student outcomes, these programs seldom reach real teachers on a large scale. Typically, reformers address such perceptions of failure by discovering and celebrating new formats and…

  7. Fixing High Schools

    ERIC Educational Resources Information Center

    Perkins-Gough, Deborah

    2005-01-01

    Reports from national education organizations in the US indicate the sorry state of high schools in the country that are accused of failing to adequately prepare their graduates for college or for the workforce, highlighting what is a serious problem in light of the troubled state of the US economy. The need to improve high schools is urgent and…

  8. Transparent electrode for optical switch

    DOEpatents

    Goldhar, J.; Henesian, M.A.

    1984-10-19

    The invention relates generally to optical switches and techniques for applying a voltage to an electro-optical crystal, and more particularly, to transparent electodes for an optical switch. System architectures for very large inertial confinement fusion (ICF) lasers require active optical elements with apertures on the order of one meter. Large aperture optical switches are needed for isolation of stages, switch-out from regenerative amplifier cavities and protection from target retroreflections.

  9. Radiation sensitive solid state switch

    NASA Technical Reports Server (NTRS)

    Hutto, R. J. (Inventor)

    1973-01-01

    A mechanically operable solid state switch suited for use in achieving a variable circuit-switching function is described. This switch is characterized by an annular array of photoresponsive switching devices, disposed in communication with an included source of radiation, and a plurality of interchangeable, mechanically operable interrupter disks. Each disk has a predetermined pattern of transparent and opaque portions. Operative displacement of each disk serves to make and break selected electrical circuits through the photo responsive devices of said array.

  10. Easily-wired toggle switch

    NASA Technical Reports Server (NTRS)

    Dean, W. T.; Stringer, E. J.

    1979-01-01

    Crimp-type connectors reduce assembly and disassembly time. With design, no switch preparation is necessary and socket contracts are crimped to wires inserted in module attached to back of toggle switch engaging pins inside module to make electrical connections. Wires are easily removed with standard detachment tool. Design can accommodate wires of any gage and as many terminals can be placed on switch as wire gage and switch dimensions will allow.

  11. Strategies for dosing and switching antipsychotics for optimal clinical management.

    PubMed

    Buckley, Peter F; Correll, Christoph U

    2008-01-01

    Optimal clinical management of schizophrenia and bipolar disorder can be achieved through careful antipsychotic dosing and, if necessary, switching to another well-chosen antipsychotic using suitable switching strategies. For severely ill patients treated in clinical practice, adequate dosing may not result from following the relatively low dosing levels and abrupt titration schedules typically used in clinical registration trials. Data from recent effectiveness trials, naturalistic studies, and the Roadmap Expert Consensus Survey provide evidence of specific dose levels and titration schedules for antipsychotic agents that may be appropriate in clinical practice. Discontinuation and frequent switching of medication are common among patients treated with antipsychotics, but data suggest that an adequate trial of the first antipsychotic medication should be undertaken before switching to another antipsychotic medication. Making a decision to switch from a typical to an atypical antipsychotic or between atypical antipsychotics should involve consideration of variables relating to the patient, illness, medication, and the patient's environment. Switching can improve efficacy and tolerability but may also result in predictable side effects or withdrawal symptoms, including weight gain and metabolic effects as well as effects associated with prolactin changes. Many side effects that occur during switching are attributable to receptor profiles and antimuscarinic or antihistaminic blockade. Individualized switching strategies that include careful choice of medication, dose, and titration and tapering schedules; management of symptoms; and patient psychoeducation can reduce or treat side effects, increasing the likelihood of a successful switch and greater adherence and efficacy.

  12. Study of switching transients in high frequency converters

    NASA Astrophysics Data System (ADS)

    Zinger, Donald S.; Elbuluk, Malik E.; Lee, Tony

    1993-06-01

    As the semiconductor technologies progress rapidly, the power densities and switching frequencies of many power devices are improved. With the existing technology, high frequency power systems become possible. Use of such a system is advantageous in many aspects. A high frequency ac source is used as the direct input to an ac/ac pulse-density-modulation (PDM) converter. This converter is a new concept which employs zero voltage switching techniques. However, the development of this converter is still in its infancy stage. There are problems associated with this converter such as a high on-voltage drop, switching transients, and zero-crossing detecting. Considering these problems, the switching speed and power handling capabilities of the MOS-Controlled Thyristor (MCT) makes the device the most promising candidate for this application. A complete insight of component considerations for building an ac/ac PDM converter for a high frequency power system is addressed. A power device review is first presented. The ac/ac PDM converter requires switches that can conduct bi-directional current and block bi-directional voltage. These bi-directional switches can be constructed using existing power devices. Different bi-directional switches for the converter are investigated. Detailed experimental studies of the characteristics of the MCT under hard switching and zero-voltage switching are also presented. One disadvantage of an ac/ac converter is that turn-on and turn-off of the switches has to be completed instantaneously when the ac source is at zero voltage. Otherwise shoot-through current or voltage spikes can occur which can be hazardous to the devices. In order for the devices to switch softly in the safe operating area even under non-ideal cases, a unique snubber circuit is used in each bi-directional switch. Detailed theory and experimental results for circuits using these snubbers are presented.

  13. Study of switching transients in high frequency converters

    NASA Technical Reports Server (NTRS)

    Zinger, Donald S.; Elbuluk, Malik E.; Lee, Tony

    1993-01-01

    As the semiconductor technologies progress rapidly, the power densities and switching frequencies of many power devices are improved. With the existing technology, high frequency power systems become possible. Use of such a system is advantageous in many aspects. A high frequency ac source is used as the direct input to an ac/ac pulse-density-modulation (PDM) converter. This converter is a new concept which employs zero voltage switching techniques. However, the development of this converter is still in its infancy stage. There are problems associated with this converter such as a high on-voltage drop, switching transients, and zero-crossing detecting. Considering these problems, the switching speed and power handling capabilities of the MOS-Controlled Thyristor (MCT) makes the device the most promising candidate for this application. A complete insight of component considerations for building an ac/ac PDM converter for a high frequency power system is addressed. A power device review is first presented. The ac/ac PDM converter requires switches that can conduct bi-directional current and block bi-directional voltage. These bi-directional switches can be constructed using existing power devices. Different bi-directional switches for the converter are investigated. Detailed experimental studies of the characteristics of the MCT under hard switching and zero-voltage switching are also presented. One disadvantage of an ac/ac converter is that turn-on and turn-off of the switches has to be completed instantaneously when the ac source is at zero voltage. Otherwise shoot-through current or voltage spikes can occur which can be hazardous to the devices. In order for the devices to switch softly in the safe operating area even under non-ideal cases, a unique snubber circuit is used in each bi-directional switch. Detailed theory and experimental results for circuits using these snubbers are presented. A current regulated ac/ac PDM converter built using MCT's and IGBT's is

  14. Illuminated push-button switch

    NASA Technical Reports Server (NTRS)

    Iwagiri, T.

    1983-01-01

    An illuminated push-button switch is described. It is characterized by the fact that is consists of a switch group, an operator button opening and closing the switch group, and a light-emitting element which illuminates the face of the operator button.

  15. Illuminated push-button switch

    NASA Astrophysics Data System (ADS)

    Iwagiri, T.

    1983-05-01

    An illuminated push-button switch is described. It is characterized by the fact that is consists of a switch group, an operator button opening and closing the switch group, and a light-emitting element which illuminates the face of the operator button.

  16. Organic Materials For Optical Switching

    NASA Technical Reports Server (NTRS)

    Cardelino, Beatriz H.

    1993-01-01

    Equations predict properties of candidate materials. Report presents results of theoretical study of nonlinear optical properties of organic materials. Such materials used in optical switching devices for computers and telecommunications, replacing electronic switches. Optical switching potentially offers extremely high information throughout in compact hardware.

  17. IGBT convertor with active snubber for soft switching. [Insulated Gate Bipolar Transistor

    NASA Technical Reports Server (NTRS)

    Masserant, B. J.; Shriver, J.; Stuart, T. A.

    1991-01-01

    This full bridge dc-dc convertor with IGBTs uses zero voltage switching (ZVS) for one leg of the bridge and zero current switching (ZCS) for the other. It is shown that an active snubber greatly improves the performance over previous methods. Experimental results are shown for a 6 kW circuit switching at 20 kHz.

  18. Route Optimization for Offloading Congested Meter Fixes

    NASA Technical Reports Server (NTRS)

    Xue, Min; Zelinski, Shannon

    2016-01-01

    The Optimized Route Capability (ORC) concept proposed by the FAA facilitates traffic managers to identify and resolve arrival flight delays caused by bottlenecks formed at arrival meter fixes when there exists imbalance between arrival fixes and runways. ORC makes use of the prediction capability of existing automation tools, monitors the traffic delays based on these predictions, and searches the best reroutes upstream of the meter fixes based on the predictions and estimated arrival schedules when delays are over a predefined threshold. Initial implementation and evaluation of the ORC concept considered only reroutes available at the time arrival congestion was first predicted. This work extends previous work by introducing an additional dimension in reroute options such that ORC can find the best time to reroute and overcome the 'firstcome- first-reroute' phenomenon. To deal with the enlarged reroute solution space, a genetic algorithm was developed to solve this problem. Experiments were conducted using the same traffic scenario used in previous work, when an arrival rush was created for one of the four arrival meter fixes at George Bush Intercontinental Houston Airport. Results showed the new approach further improved delay savings. The suggested route changes from the new approach were on average 30 minutes later than those using other approaches, and fewer numbers of reroutes were required. Fewer numbers of reroutes reduce operational complexity and later reroutes help decision makers deal with uncertain situations.

  19. CMOS analog switches for adaptive filters

    NASA Technical Reports Server (NTRS)

    Dixon, C. E.

    1980-01-01

    Adaptive active low-pass filters incorporate CMOS (Complimentary Metal-Oxide Semiconductor) analog switches (such as 4066 switch) that reduce variation in switch resistance when filter is switched to any selected transfer function.

  20. Fixed pitch rotor performance of large horizontal axis wind turbines

    NASA Technical Reports Server (NTRS)

    Viterna, L. A.; Corrigan, R. D.

    1982-01-01

    Experimental fixed pitch wind turbine performance data is presented for both the DOE/NASA Mod-0 and the Danish Gedser wind turbines. Furthermore, a method for calculating the output power from large fixed pitch wind turbines is presented. Modifications to classical blade element momentum theory are given that improve correlation with measured data. Improvement is particularly evident in high winds (low tip speed ratios) where aerodynamic stall occurs as the blade experiences high angles of attack.

  1. Complex Life Cycles in a Variable Environment: Predicting When the Timing of Metamorphosis Shifts from Resource Dependent to Developmentally Fixed.

    PubMed

    Hentschel

    1999-11-01

    To test models of the timing of and size at metamorphosis, researchers manipulate food at several times during the larval phase of an animal's complex life cycle. Data from diverse taxa show that the age at metamorphosis becomes resource independent (i.e., fixed) at some point during the larval phase. Although existing models have been modified to incorporate a fixed rate of development, none predicts when phenotypic plasticity in metamorphic timing is lost. A graphical model is presented that extends knowledge of a genotype's optimal age and size at metamorphosis in different environments in which resources remain constant throughout the larval phase (i.e., the genotype's reaction norm) to predict when development rate becomes fixed in response to resource variability during the larval phase. Model predictions concur with data from food-switching experiments on anuran tadpoles and barnacle nauplii. As interest in the timing of and size at metamorphosis expands from well-studied taxa (e.g., amphibians) to the many others that have complex life cycles, the predictive model provides a useful tool to design and improve experiments.

  2. Differences in night-time and daytime ambulatory blood pressure when diurnal periods are defined by self-report, fixed-times, and actigraphy: Improving the Detection of Hypertension study.

    PubMed

    Booth, John N; Muntner, Paul; Abdalla, Marwah; Diaz, Keith M; Viera, Anthony J; Reynolds, Kristi; Schwartz, Joseph E; Shimbo, Daichi

    2016-02-01

    To determine whether defining diurnal periods by self-report, fixed-time, or actigraphy produce different estimates of night-time and daytime ambulatory blood pressure (ABP). Over a median of 28 days, 330 participants completed two 24-h ABP and actigraphy monitoring periods with sleep diaries. Fixed night-time and daytime periods were defined as 0000-0600 h and 1000-2000 h, respectively. Using the first ABP period, within-individual differences for mean night-time and daytime ABP and kappa statistics for night-time and daytime hypertension (systolic/diastolic ABP≥120/70 mmHg and ≥135/85 mmHg, respectively) were estimated comparing self-report, fixed-time, or actigraphy for defining diurnal periods. Reproducibility of ABP was also estimated. Within-individual mean differences in night-time systolic ABP were small, suggesting little bias, when comparing the three approaches used to define diurnal periods. The distribution of differences, represented by 95% confidence intervals (CI), in night-time systolic and diastolic ABP and daytime systolic and diastolic ABP was narrowest for self-report versus actigraphy. For example, mean differences (95% CI) in night-time systolic ABP for self-report versus fixed-time was -0.53 (-6.61, +5.56) mmHg, self-report versus actigraphy was 0.91 (-3.61, +5.43) mmHg, and fixed-time versus actigraphy was 1.43 (-5.59, +8.46) mmHg. Agreement for night-time and daytime hypertension was highest for self-report versus actigraphy: kappa statistic (95% CI) = 0.91 (0.86,0.96) and 1.00 (0.98,1.00), respectively. The reproducibility of mean ABP and hypertension categories was similar using each approach. Given the high agreement with actigraphy, these data support using self-report to define diurnal periods on ABP monitoring. Further, the use of fixed-time periods may be a reasonable alternative approach.

  3. High gain GaAs photoconductive semiconductor switches: Switch longevity

    SciTech Connect

    Loubriel, G.M.; Zutavern, F.J.; Mar, A.

    1998-07-01

    Optically activated, high gain GaAs switches are being tested for many different pulsed power applications that require long lifetime (longevity). The switches have p and n contact metallization (with intentional or unintentional dopants) configured in such a way as to produce p-i-n or n-i-n switches. The longevity of the switches is determined by circuit parameters and by the ability of the contacts to resist erosion. This paper will describe how the switches performed in test-beds designed to measure switch longevity. The best longevity was achieved with switches made with diffused contacts, achieving over 50 million pulses at 10 A and over 2 million pulses at 80 A.

  4. Micro Electro Mechanical Systems (MEMS) Micro-Switches for Use in DC, RF, and Optical Applications

    NASA Astrophysics Data System (ADS)

    Suzuki, Kenichiro

    2002-06-01

    Micromachined micro-switches have stimulated the development of the core infrastructure technology for the next generation communication systems because of their superior performance. They are fabricated by similar silicon micromachined processes, but the switch structure and its characteristics depend on each application. Micro electro mechanical systems (MEMS) technology has been applied to micro relays, RF switches, and optical switches; as a result, optical and mechanical performance has been improved.

  5. Fixed drug eruption to sitagliptin.

    PubMed

    Gupta, Mrinal; Gupta, Anish

    2015-01-01

    Fixed drug eruption is a common adverse effect seen with various drugs notably antibiotics, antiepileptics and non-steroidal anti-inflammatory drugs. Herein we report a case of Sitagliptin induced fixed drug eruption in a 46 year old female who developed circumscribed, erythematous macules all over the body within one week of initiation of Sitagliptin. The lesions resolved with residual hyperpigmentation on cessation of the drug. The diagnosis was confirmed by an oral provocation test which led to a reactivation of the lesions. To the best of our knowledge, this is the first case of fixed drug eruption to Sitagliptin reported in the literature.

  6. Fixed drug eruption to propofol.

    PubMed

    Allchurch, L G V; Crilly, H

    2014-11-01

    We present a case of fixed drug eruption to propofol following a series of sedations of a patient for a number of day case procedures. The patient experienced oedema and blistering of his penis, increasing in severity and duration following each subsequent exposure. The diagnosis was confirmed by punch biopsy following an intravenous challenge test with propofol. Whilst reports of fixed drug eruptions to anaesthetic induction agents are uncommon, a number of drugs used commonly by anaesthetists are known triggers. We discuss fixed drug eruptions in relation to anaesthetic practice, aiming to raise awareness of this adverse drug reaction.

  7. Sonic crystal acoustic switch device.

    PubMed

    Alagoz, Serkan; Alagoz, Baris Baykant

    2013-06-01

    This study reports a wave-controlled sonic crystal switch device that exhibits a destructive interference-based wave to wave reverse switching effect. By applying control waves, this acoustic device, composed of a two-dimensional square lattice sonic crystal block, reduces acoustic wave transmission from input to output. The finite difference time domain simulation and experimental results confirm the wave-to-wave reverse switching effect at the peak frequencies of the second band. The proposed sonic crystal switch prototype provides a contrast rate of 86% at 11.3 kHz frequency. This wave-to-wave switching effect is useful for controlling wave propagation for smart structure applications.

  8. Plasma opening switch

    DOEpatents

    Savage, Mark E.; Mendel, Jr., Clifford W.

    2001-01-01

    A command triggered plasma opening switch assembly using an amplification stage. The assembly surrounds a coaxial transmission line and has a main plasma opening switch (POS) close to the load and a trigger POS upstream from the main POS. The trigger POS establishes two different current pathways through the assembly depended on whether it has received a trigger current pulse. The initial pathway has both POS's with plasma between their anodes and cathodes to form a short across the transmission line and isolating the load. The final current pathway is formed when the trigger POS receives a trigger current pulse which energizes its fast coil to push the conductive plasma out from between its anode and cathode, allowing the main transmission line current to pass to the fast coil of the main POS, thus pushing its plasma out the way so as to establish a direct current pathway to the load.

  9. Future switching satellites

    NASA Technical Reports Server (NTRS)

    Campanella, S. Joseph; Pontano, Benjamin A.; Chalmers, Harvey

    1988-01-01

    Communications satellites of the future are likely to use much narrower beams in order to increase the uplink G/T and the downlink EIRP so that small earth terminals of the VSAT class can achieve full mesh connectivity. These satellites will need onboard switches to route traffic from originating upbeams to destination downbeams. This paper presents a new approach to accomplishing this rerouting using destination-directed packets that inherently carry the information needed to control the onboard switch connections and to adjust the traffic flow among the beams and the stations. The method also inherently provides channel multiplication and DAMA advantages which result in maximally efficient utilization of the space segment resource.

  10. Switched Matrix Accelerator

    SciTech Connect

    Whittum, David H

    2000-10-04

    We describe a new concept for a microwave circuit functioning as a charged-particle accelerator at mm-wavelengths, permitting an accelerating gradient higher than conventional passive circuits can withstand consistent with cyclic fatigue. The device provides acceleration for multiple bunches in parallel channels, and permits a short exposure time for the conducting surface of the accelerating cavities. Our analysis includes scalings based on a smooth transmission line model and a complementary treatment with a coupled-cavity simulation. We provide also an electromagnetic design for the accelerating structure, arriving at rough dimensions for a seven-cell accelerator matched to standard waveguide and suitable for bench tests at low power in air at 91.392. GHz. A critical element in the concept is a fast mm-wave switch suitable for operation at high-power, and we present the considerations for implementation in an H-plane tee. We discuss the use of diamond as the photoconductor switch medium.

  11. Optical fiber switch

    DOEpatents

    Early, James W.; Lester, Charles S.

    2002-01-01

    Optical fiber switches operated by electrical activation of at least one laser light modulator through which laser light is directed into at least one polarizer are used for the sequential transport of laser light from a single laser into a plurality of optical fibers. In one embodiment of the invention, laser light from a single excitation laser is sequentially transported to a plurality of optical fibers which in turn transport the laser light to separate individual remotely located laser fuel ignitors. The invention can be operated electro-optically with no need for any mechanical or moving parts, or, alternatively, can be operated electro-mechanically. The invention can be used to switch either pulsed or continuous wave laser light.

  12. Cryogenic switched MOSFET characterization

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Both p channel and n channel enhancement mode MOSFETs can be readily switched on and off at temperatures as low as 2.8 K so that switch sampled readout of a VLWIR Ge:Ga focal plane is electronically possible. Noise levels as low as 100 rms electrons per sample (independent of sample rate) can be achieved using existing p channel MOSFETs, at overall rates up to 30,000 samples/second per multiplexed channel (e.g., 32 detectors at a rate of almost 1,000 frames/second). Run of the mill devices, including very low power dissipation n channel FETs would still permit noise levels of the order of 500 electrons/sample.

  13. The quantum cryptographic switch

    NASA Astrophysics Data System (ADS)

    Srinatha, N.; Omkar, S.; Srikanth, R.; Banerjee, Subhashish; Pathak, Anirban

    2014-01-01

    We illustrate the principle of a cryptographic switch for a quantum scenario, in which a third party (Charlie) can control to a continuously varying degree the amount of information the receiver (Bob) receives, after the sender (Alice) has sent her information through a quantum channel. Suppose Charlie transmits a Bell state to Alice and Bob. Alice uses dense coding to transmit two bits to Bob. Only if the 2-bit information corresponding to the choice of the Bell state is made available by Charlie to Bob can the latter recover Alice's information. By varying the amount of information Charlie gives, he can continuously alter the information recovered by Bob. The performance of the protocol as subjected to the squeezed generalized amplitude damping channel is considered. We also present a number of practical situations where a cryptographic switch would be of use.

  14. MULTIPLE SPARK GAP SWITCH

    DOEpatents

    Schofield, A.E.

    1958-07-22

    A multiple spark gap switch of unique construction is described which will permit controlled, simultaneous discharge of several capacitors into a load. The switch construction includes a disc electrode with a plurality of protuberances of generally convex shape on one surface. A firing electrode is insulatingly supponted In each of the electrode protuberances and extends substantially to the apex thereof. Individual electrodes are disposed on an insulating plate parallel with the disc electrode to form a number of spark gaps with the protuberances. These electrodes are each connected to a separate charged capacitor and when a voltage ls applied simultaneously between the trigger electrodes and the dlsc electrode, each spark gap fires to connect its capacitor to the disc electrode and a subsequent load.

  15. Many-Body Switches

    NASA Astrophysics Data System (ADS)

    MacDonald, Allan H.

    2014-03-01

    Most current electronic devices use gate voltages to switch individual electron transport channels or off. This architecture necessarily leads to operating voltages that are much larger than the temperature thermal energy, and places lower bounds on power consumption that are becoming. I will discuss strategies for achieving devices in which gates are used to collective many-electron states, in principle allowing charge transport to be switched by smaller voltage changes and both operating voltages and power consumption to reduced. I will specifically address devices based on the properties of itinerant electroninsulating magnetic systems, and devices based on bilayer exciton condensation. This work is based on work performed in collaboration with Sanjay Banerjee and Frank Register.

  16. Nonlinear magnetic field transport in opening switch plasmas

    SciTech Connect

    Mason, R.J. ); Auer, P.L.; Sudan, R.N.; Oliver, B.V.; Seyler, C.E.; Greenly, J.B. )

    1993-04-01

    The nonlinear transport of magnetic field in collisionless plasmas, as present in the plasma opening switch (POS), using the implicit multifluid simulation code ANTHEM [J. Comput. Phys. [bold 71], 429 (1987)] is studied. The focus is on early time behavior in the electron--magnetohydrodynamic (EMHD) limit, with the ions fixed, and the electrons streaming as a fluid under the influence of [bold v][sub [ital e

  17. Automatic switching matrix

    DOEpatents

    Schlecht, Martin F.; Kassakian, John G.; Caloggero, Anthony J.; Rhodes, Bruce; Otten, David; Rasmussen, Neil

    1982-01-01

    An automatic switching matrix that includes an apertured matrix board containing a matrix of wires that can be interconnected at each aperture. Each aperture has associated therewith a conductive pin which, when fully inserted into the associated aperture, effects electrical connection between the wires within that particular aperture. Means is provided for automatically inserting the pins in a determined pattern and for removing all the pins to permit other interconnecting patterns.

  18. Composite Material Switches

    NASA Technical Reports Server (NTRS)

    Javadi, Hamid (Inventor)

    2001-01-01

    A device to protect electronic circuitry from high voltage transients is constructed from a relatively thin piece of conductive composite sandwiched between two conductors so that conduction is through the thickness of the composite piece. The device is based on the discovery that conduction through conductive composite materials in this configuration switches to a high resistance mode when exposed to voltages above a threshold voltage.

  19. CREE: Making the Switch

    SciTech Connect

    Grider, David; Palmer, John

    2014-03-06

    CREE, with the help of ARPA-E funding, has developed a Silicon Carbide (SIC) transistor which can be used to create solid state transformers capable of meeting the unique needs of the emerging smart grid. SIC transistors are different from common silicon computer chips in that they handle grid scale voltages with ease and their high frequency switching is well suited to the intermittent nature of renewable energy generation.

  20. CREE: Making the Switch

    ScienceCinema

    Grider, David; Palmer, John

    2016-07-12

    CREE, with the help of ARPA-E funding, has developed a Silicon Carbide (SIC) transistor which can be used to create solid state transformers capable of meeting the unique needs of the emerging smart grid. SIC transistors are different from common silicon computer chips in that they handle grid scale voltages with ease and their high frequency switching is well suited to the intermittent nature of renewable energy generation.