Three-phase power factor controller with induced EMF sensing
NASA Technical Reports Server (NTRS)
Nola, F. J. (Inventor)
1984-01-01
A power factor controller for an ac induction motor is provided which is of the type comprising thyristor switches connected in series with the motor, phase detectors for sensing the motor current and voltage and providing an output proportional to the phase difference between the motor voltage and current, and a control circuit, responsive to the output of the phase detector and to a power factor command signal, for controlling switching of the thyristor. The invention involves sensing the induced emf produced by the motor during the time interval when the thyristor is off and for producing a corresponding feedback signal for controlling switching of the thyristor. The sensed emf is also used to enhance soft starting of the motor.
Downhower, Jr., Francis H.; Finlayson, Paul T.
1984-04-10
A snubber circuit coupled across each thyristor to be gated in a chain of thyristors determines the critical output of a NOR LATCH whenever one snubber circuit could not be charged and discharged under normal gating conditions because of a short failure.
NASA Astrophysics Data System (ADS)
Roy, M.; Sengupta, M.
2012-09-01
Induction heating is a non-contact heating process which became popular due to its energy efficiency. Current source inverter (CSI) based induction heating units are commonly used in the industry. Most of these CSIs are thyristor based, since thyristors of higher ratings are easily available. These being load commutated apparatus a start-up circuit is needed to initiate commutation. In this paper the design and fabrication of two laboratory prototypes have been presented. The first one, a SCR-based CSI fed controlled induction heating unit (IHU), has been tested with two different types of start-up procedures. Thereafter the fabrication and performance of another IGBT-based CSI is compared with the thyristor-based CSI for a 2 kW, 10 kHz application. These two types of CSIs are fully fabricated in laboratory along with the IHU. Performance analysis and simulation of two different CSIs has been done by using SequelGUI2. The triggering pulses for the inverter devices (for both CSI devices as well as auxilliary thyristor of start-up circuit) have been generated and closed-loop control has been done in FPGA platform built around an Altera make cyclone EPIC12Q240C processor which can be programmed using Quartus II software. Close agreement between simulated and experimental results highlight the accuracy of the experimental work.
Solid-state circuit breaker with current-limiting characteristic using a superconducting coil
Boenig, H.J.
1982-08-16
A thyristor bridge interposes an ac source and a load. A series connected DC source and superconducting coil within the bridge biases the thyristors thereof so as to permit bidirectional ac current flow therethrough under normal operating conditions. Upon a fault condition a control circuit triggers the thyristors so as to reduce ac current flow therethrough to zero in less than two eyeles and to open the bridge thereafter. Upon a temporary overload condition the control circuit triggers the thyristors so as to limit ac current flow therethrough to an acceptable level.
Solid-state circuit breaker with current limiting characteristic using a superconducting coil
Boenig, Heinrich J.
1984-01-01
A thyristor bridge interposes an ac source and a load. A series connected DC source and superconducting coil within the bridge biases the thyristors thereof so as to permit bidirectional ac current flow therethrough under normal operating conditions. Upon a fault condition a control circuit triggers the thyristors so as to reduce ac current flow therethrough to zero in less than two cycles and to open the bridge thereafter. Upon a temporary overload condition the control circuit triggers the thyristors so as to limit ac current flow therethrough to an acceptable level.
Input Power Characteristics of the Thyristor Variable Voltage Power Conditioner
DOT National Transportation Integrated Search
1973-11-01
A laboratory study was made of transformer and thyristor voltage control for speed control of a rotary induction motor. The test program consisted of two parts; the first dealing with measurements of the induction motor characteristics and the second...
Fault current limiter and alternating current circuit breaker
Boenig, Heinrich J.
1998-01-01
A solid-state circuit breaker and current limiter for a load served by an alternating current source having a source impedance, the solid-state circuit breaker and current limiter comprising a thyristor bridge interposed between the alternating current source and the load, the thyristor bridge having four thyristor legs and four nodes, with a first node connected to the alternating current source, and a second node connected to the load. A coil is connected from a third node to a fourth node, the coil having an impedance of a value calculated to limit the current flowing therethrough to a predetermined value. Control means are connected to the thyristor legs for limiting the alternating current flow to the load under fault conditions to a predetermined level, and for gating the thyristor bridge under fault conditions to quickly reduce alternating current flowing therethrough to zero and thereafter to maintain the thyristor bridge in an electrically open condition preventing the alternating current from flowing therethrough for a predetermined period of time.
Fault current limiter and alternating current circuit breaker
Boenig, H.J.
1998-03-10
A solid-state circuit breaker and current limiter are disclosed for a load served by an alternating current source having a source impedance, the solid-state circuit breaker and current limiter comprising a thyristor bridge interposed between the alternating current source and the load, the thyristor bridge having four thyristor legs and four nodes, with a first node connected to the alternating current source, and a second node connected to the load. A coil is connected from a third node to a fourth node, the coil having an impedance of a value calculated to limit the current flowing therethrough to a predetermined value. Control means are connected to the thyristor legs for limiting the alternating current flow to the load under fault conditions to a predetermined level, and for gating the thyristor bridge under fault conditions to quickly reduce alternating current flowing therethrough to zero and thereafter to maintain the thyristor bridge in an electrically open condition preventing the alternating current from flowing therethrough for a predetermined period of time. 9 figs.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Matinyan, A. M., E-mail: al-drm@mail.ru; Peshkov, M. V.; Karpov, V. N.
2016-09-15
The design and current spectrum of a thyristor valve controlled shunt reactor (TCSR) with split valveside windings are described. The dependence of the amplitudes of higher-order harmonics of the power winding current on the TCSR operating regime are presented for this TCSR design.
NASA Astrophysics Data System (ADS)
Yashvantrai Vyas, Bhargav; Maheshwari, Rudra Prakash; Das, Biswarup
2016-06-01
Application of series compensation in extra high voltage (EHV) transmission line makes the protection job difficult for engineers, due to alteration in system parameters and measurements. The problem amplifies with inclusion of electronically controlled compensation like thyristor controlled series compensation (TCSC) as it produce harmonics and rapid change in system parameters during fault associated with TCSC control. This paper presents a pattern recognition based fault type identification approach with support vector machine. The scheme uses only half cycle post fault data of three phase currents to accomplish the task. The change in current signal features during fault has been considered as discriminatory measure. The developed scheme in this paper is tested over a large set of fault data with variation in system and fault parameters. These fault cases have been generated with PSCAD/EMTDC on a 400 kV, 300 km transmission line model. The developed algorithm has proved better for implementation on TCSC compensated line with its improved accuracy and speed.
NASA Ames Research Center 60 MW Power Supply Modernization
NASA Technical Reports Server (NTRS)
Choy, Yuen Ching; Ilinets, Boris V.; Miller, Ted; Nagel, Kirsten (Technical Monitor)
2001-01-01
The NASA Ames Research Center 60 MW DC Power Supply was built in 1974 to provide controlled DC power for the Thermophysics Facility Arc Jet Laboratory. The Power Supply has gradually losing reliability due to outdated technology and component life limitation. NASA has decided to upgrade the existing rectifier modules with contemporary high-power electronics and control equipment. NASA plans to complete this project in 2001. This project includes a complete replacement of obsolete thyristor stacks in all six rectifier modules and rectifier bridge control system. High power water-cooled thyristors and freewheeling diodes will be used. The rating of each of the six modules will be 4000 A at 5500 V. The control firing angle signal will be sent from the Facility Control System to six modules via fiberoptic cable. The Power Supply control and monitoring system will include a Master PLC in the Facility building and a Slave PLC in each rectifier module. This system will also monitor each thyristor level in each stack and the auxiliary equipment.
Fast Turn-Off Times Observed in Experimental 4H SiC Thyristors
NASA Technical Reports Server (NTRS)
Niedra, Janis M.
2006-01-01
Room temperature measurements of the turn-off time (t(sub q)) are reported for several packaged, npnp developmental power thyristors based on 4H-type SiC and rated 400 V, 2 A. Turn-off is effected by a 50 V pulse of applied reverse voltage, from a state of a steady 1 A forward current. Plots of t(sub q) against the ramp rate (dV(sub AK)/dt) of reapplied forward voltage are presented for preset values of limiting anode-to-cathode voltage (V(sub AK,max)). The lowest t(sub q) measured was about 180 ns. A rapid rise of these t(sub q) curves was observed for values of V(sub AK,max) that are only about a fifth of the rated voltage, whereas comparative t(sub q) plots for a commercial, fast turn-off, Si-based thyristor at a proportionately reduced V(sub AK,max) showed no such behavior. Hence these SiC thyristors may have problems arising from material defects or surface passivation. The influence the R-C-D gate bypass circuit that was used is briefly discussed.
Two dimensional thermal and charge mapping of power thyristors
NASA Technical Reports Server (NTRS)
Hu, S. P.; Rabinovici, B. M.
1975-01-01
The two dimensional static and dynamic current density distributions within the junction of semiconductor power switching devices and in particular the thyristors were obtained. A method for mapping the thermal profile of the device junctions with fine resolution using an infrared beam and measuring the attenuation through the device as a function of temperature were developed. The results obtained are useful in the design and quality control of high power semiconductor switching devices.
NASA Technical Reports Server (NTRS)
Edmond, John A. (Inventor); Palmour, John W. (Inventor)
1996-01-01
The SiC thyristor has a substrate, an anode, a drift region, a gate, and a cathode. The substrate, the anode, the drift region, the gate, and the cathode are each preferably formed of silicon carbide. The substrate is formed of silicon carbide having one conductivity type and the anode or the cathode, depending on the embodiment, is formed adjacent the substrate and has the same conductivity type as the substrate. A drift region of silicon carbide is formed adjacent the anode or cathode and has an opposite conductivity type as the anode or cathode. A gate is formed adjacent the drift region or the cathode, also depending on the embodiment, and has an opposite conductivity type as the drift region or the cathode. An anode or cathode, again depending on the embodiment, is formed adjacent the gate or drift region and has an opposite conductivity type than the gate.
Use of TCSR with Split Windings for Shortening the Spar Cycle Time in 500 kV Lines
DOE Office of Scientific and Technical Information (OSTI.GOV)
Matinyan, A. M., E-mail: al-drm@mail.ru; Peshkov, M. V.; Karpov, V. N.
The arc-fault recharge phenomenon in single-phase automatic reclosure (SPAR) of a line is examined. Abrief description is given of the design of a 500 kV thyristor controlled shunt reactor (TCSR) with split valve-side windings. This type of TCSR is shown to effectively quench a single-phase arc fault in a power transmission line and shortens the SPAR cycle time.
Scheme for rapid adjustment of network impedance
Vithayathil, John J.
1991-01-01
A static controlled reactance device is inserted in series with an AC electric power transmission line to adjust its transfer impedance. An inductor (reactor) is serially connected with two back-to-back connected thyristors which control the conduction period and hence the effective reactance of the inductor. Additional reactive elements are provided in parallel with the thyristor controlled reactor to filter harmonics and to obtain required range of variable reactance. Alternatively, the static controlled reactance device discussed above may be connected to the secondary winding of a series transformer having its primary winding connected in series to the transmission line. In a three phase transmission system, the controlled reactance device may be connected in delta configuration on the secondary side of the series transformer to eliminate triplen harmonics.
A hybrid electromechanical solid state switch for ac power control
NASA Technical Reports Server (NTRS)
1972-01-01
Bidirectional thyristor coupled to a series of actuator driven electromechanical contacts generates hybrid electromechanical solid state switch for ac power control. Device is useful in power control applications where zero crossover switching is required.
NASA Technical Reports Server (NTRS)
Lock, K.; Patalong, H.; Platzoeder, K.
1979-01-01
Using neutron irradiated silicon with considerably lower spread in resistivity as compared to conventionally doped silicon it was possible to produce power thyristors with breakdown voltages between 3.5 kV and 5.5 kV. The thyristor pellets have a diameter of 50 mm. Maximum average on-state currents of 600 to 800 A can be reached with these elements. The dynamic properties of the thryistors could be improved to allow standard applications up to maximum repetitive voltages of 4.5 kV.
A unique power supply for the PEP II klystron at SLAC
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cassel, R.; Nguyen, M.N.
1997-07-01
Each of the eight 1.2 MW RF klystrons for the PEP-II storage rings require a 2.5 MVA DC power supply of 83 Kv at 23 amps. The design for the supply was base on three factors, low cost, small size to fit existing substation pads, and good protection against damage to the klystron including klystron gun arcs. The supply uses a 12 pulse 12.5 KV primary thyristor star point controller with primary filter inductor to provide rapid voltage control, good voltage regulation, and fast turn off during klystron tube faults. The supply also uses a unique secondary rectifier, filter capacitormore » configuration to minimize the energy available under a klystron fault. The voltage control is from 0--90 KV with a regulation of < 0.1% and voltage ripple of < 1% P-P, (< 0.2% RMS) above 60 KV. The supply utilizes a thyristor crowbar, which under a klystron tube arc limits the energy in the klystron arc to < 5 joules. If the thyristor crowbar is disabled the energy supplied is < 40 joules into the arc. The size of the supply was reduced small enough to fit the existing PEP transformer yard pads. The cost of the power supply was < $140 per KVA.« less
Development of a 1000V, 200A, low-loss, fast-switching, gate-assisted turn-off thyristor
NASA Technical Reports Server (NTRS)
Schlegel, E. S.; Lowry, L. R.
1975-01-01
Feasibility was demonstrated for a thyristor that blocks 1000V forward and reverse, conducts 200A, and turns on in little more than 2 microsec with only 2A of gate drive. Its features include a turn-off time of 3 microsec achieved with 2A of gate assist current of a few microseconds duration and an energy dissipation of only 12 mJ per pulse for a 20 microsec half sine wave, 200A pulse. Extensive theoretical and experimental study of the electrical behavior of thyristors having a fast turn-off time have significantly improved the understanding of the physics of turning thyristor off. Thyristors of two new designs were fabricated and evaluated. The high speed and low power were achieved by a combination of gate amplification, cathode shunting, and gate-assisted turn-off. Two techniques for making this combination practical are described.
NASA Astrophysics Data System (ADS)
Grube, R.; Tursky, W.; Gerzovskovits, S.; Schierz, W.
1982-12-01
An asymmetrical gate assisted turn-off thyristor and two types of rectifier diodes were developed. These devices are suitable for self-commutated convertors working at frequencies between 15 and 30 kHz for direct connection to 380 V and 500 V lines and for power outputs up to 20 kVA. Such convertors allow economic and easily controllable power supplies to be realized for applications such as welding, inductive heating, ultrasonic generators, and radar modulators.
Method of controlling switching of a multiphase inductor-converter bridge
Kustom, Robert L.; Fuja, Raymond E.
1981-01-01
In an inductor-convertor circuit for transferring electrical energy between a storage coil and a load coil using a storage thyristor bridge, a load thyristor bridge, and a set of commutating capacitors, operation is improved by a method of changing the rate of delivery of energy in a given direction. The change in rate corresponds to a predetermined change in phase angle between the load bridge and the storage bridge and comprises changing the phase of the bridge by two steps, each equal to half the predetermined change and occurring 180.degree. apart. The method assures commutation and minimizes imbalances that lead otherwise to overvoltages.
Phase detector for three-phase power factor controller
NASA Technical Reports Server (NTRS)
Nola, F. J. (Inventor)
1984-01-01
A phase detector for the three phase power factor controller (PFC) is described. The phase detector for each phase includes an operational amplifier which senses the current phase angle for that phase by sensing the voltage across the phase thyristor. Common mode rejection is achieved by providing positive feedback between the input and output of the voltage sensing operational amplifier. this feedback preferably comprises a resistor connected between the output and input of the operational amplifier. The novelty of the invention resides in providing positive feedback such that switching of the operational amplifier is synchronized with switching of the voltage across the thyristor. The invention provides a solution to problems associated with high common mode voltage and enables use of lower cost components than would be required by other approaches.
Method of controlling switching of a multiphase inductor-converter bridge. [Patent application
Kustom, R.L.; Fuja, R.E.
In an inductor-convertor circuit for transferring electrical energy between a storage coil and a load coil through a storage thyristor bridge, a load thyristor bridge, and a set of commutating capacitors, operation is improved by a method of changing the rate of delivery of energy in a given direction. The change in rate corresponds to a predetermined change in phase angle between the load bridge and the storage bridge, and comprises changing the phase of the bridge by two steps, each equal to half the predetermined change and occurring 180/sup 0/ apart. The method assures commutation and minimizes imbalances that lead otherwise to overvoltages. 11 figures.
de Morais Sousa, Kleiton; Probst, Werner; Bortolotti, Fernando; Martelli, Cicero; da Silva, Jean Carlos Cardozo
2014-09-05
This work reports the thermal modeling and characterization of a thyristor. The thyristor is used in a 6.5-MW generator excitation bridge. Temperature measurements are performed using fiber Bragg grating (FBG) sensors. These sensors have the benefits of being totally passive and immune to electromagnetic interference and also multiplexed in a single fiber. The thyristor thermal model consists of a second order equivalent electric circuit, and its power losses lead to an increase in temperature, while the losses are calculated on the basis of the excitation current in the generator. Six multiplexed FBGs are used to measure temperature and are embedded to avoid the effect of the strain sensitivity. The presented results show a relationship between field current and temperature oscillation and prove that this current can be used to determine the thermal model of a thyristor. The thermal model simulation presents an error of 1.5 °C, while the FBG used allows for the determination of the thermal behavior and the field current dependence. Since the temperature is a function of the field current, the corresponding simulation can be used to estimate the temperature in the thyristors.
de Morais Sousa, Kleiton; Probst, Werner; Bortolotti, Fernando; Martelli, Cicero; da Silva, Jean Carlos Cardozo
2014-01-01
This work reports the thermal modeling and characterization of a thyristor. The thyristor is used in a 6.5-MW generator excitation bridge. Temperature measurements are performed using fiber Bragg grating (FBG) sensors. These sensors have the benefits of being totally passive and immune to electromagnetic interference and also multiplexed in a single fiber. The thyristor thermal model consists of a second order equivalent electric circuit, and its power losses lead to an increase in temperature, while the losses are calculated on the basis of the excitation current in the generator. Six multiplexed FBGs are used to measure temperature and are embedded to avoid the effect of the strain sensitivity. The presented results show a relationship between field current and temperature oscillation and prove that this current can be used to determine the thermal model of a thyristor. The thermal model simulation presents an error of 1.5 °C, while the FBG used allows for the determination of the thermal behavior and the field current dependence. Since the temperature is a function of the field current, the corresponding simulation can be used to estimate the temperature in the thyristors. PMID:25198007
Silicon Carbide Emitter Turn-Off Thyristor
Wang, Jun; Wang, Gangyao; Li, Jun; ...
2008-01-01
A novel MOS-conmore » trolled SiC thyristor device, the SiC emitter turn-off thyristor (ETO) is a promising technology for future high-voltage switching applications because it integrates the excellent current conduction capability of a SiC thyristor with a simple MOS-control interface. Through unity-gain turn-off, the SiC ETO also achieves excellent Safe Operation Area (SOA) and faster switching speeds than silicon ETOs. The world's first 4.5-kV SiC ETO prototype shows a forward voltage drop of 4.26 V at 26.5 A / cm 2 current density at room and elevated temperatures. Tested in an inductive circuit with a 2.5 kV DC link voltage and a 9.56-A load current, the SiC ETO shows a fast turn-off time of 1.63 microseconds and a low 9.88 mJ turn-off energy. The low switching loss indicates that the SiC ETO could operate at about 4 kHz if 100 W / cm 2 conduction and the 100 W / cm 2 turn-off losses can be removed by the thermal management system. This frequency capability is about 4 times higher than 4.5-kV-class silicon power devices. The preliminary demonstration shows that the SiC ETO is a promising candidate for high-frequency, high-voltage power conversion applications, and additional developments to optimize the device for higher voltage (>5 kV) and higher frequency (10 kHz) are needed.« less
2008-05-02
conduction capacity of the discharge switch; the discharge switch was a TRIAC (Littlefuse – Q6015L5) rated to block 600Vand conduct 15A. (For this circuit ...part of the test circuit to verify was the capacitor dump circuit . The capacitor bank was charged up to 200V and the TRIAC (S2 in Figure 17) was...be turned off by a GTO thyristor. During the course of the project, a series of GTO thyristors were used in an inductive pulse forming circuit to
Development of a 1000V, 200A, low-loss, fast-switching, gate-assisted turn-off thyristor
NASA Technical Reports Server (NTRS)
Schlegel, E. S.; Lowry, L. R.; Moore, D. L.
1977-01-01
The results of a program to develop a fast high power thyristor that can operate in switching circuits at frequencies of 10 to 20 kHz with very low power loss are given. Feasibility was demonstrated for a thyristor that blocks 1000V forward and reverse, conducts 200A, turns on in little more than 2 more microseconds with only 2A of gate drive, turns off in 3 microseconds with 2A of gate assist current and has an energy dissipation of only 12 mJ per pulse for a 20 microsecond half sine wave 200A pulse. Data were generated that clearly showed the tradeoffs that can be made between the turn off time and forward drop. The understanding of this relationship is necessary in the selection of deliverable thyristors with turn off times up to 7 microseconds to give improved efficiency in a series resonant dc to dc inverter application.
A new inverter topology using GTO commutation. [Gate Turn Off thyristor
NASA Technical Reports Server (NTRS)
Rippel, W. E.
1983-01-01
A new N-phase, forced commutated bridge inverter topology has been developed wherein a single Gate Turn Off Thyristor (GTO) is used to commutate each of 2N main Thyristors (SCRs). Since, for most applications, the primary loss mechanism is the SCR forward drop, very high efficiencies are possible. Compared with conventional pure SCR and pure GTO inverters, cost per kW is lower - in the former case due to the large cost differential between GTOs and SCRs. Other advantages of the new inverter include high power density, low switching losses and stresses, modulation flexibility and amenability to high voltage and high frequency operation.
Effect of Frequency and Spatial-Harmonics on Rotary and Linear Induction Motor Characteristics
DOT National Transportation Integrated Search
1972-03-01
A computer analysis is made of the effect of current and MMF airgap harmonics on the output characteristics of rotary and linear induction motors. The current harmonics accompanying thyristor-control operation are evaluated by Fourier analyzing the p...
Regenerative Snubber For GTO-Commutated SCR Inverter
NASA Technical Reports Server (NTRS)
Rippel, Wally E.; Edwards, Dean B.
1992-01-01
Proposed regenerative snubbing circuit substituted for dissipative snubbing circuit in inverter based on silicon controlled rectifiers (SCR's) commutated by gate-turn-off thyristor (GTO). Intended to reduce loss of power that occurs in dissipative snubber. Principal criteria in design: low cost, simplicity, and reliability.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Narayanan, S.S.Y.; Ananthakrishnan, P.; Hangari, V.U.
1995-12-31
A brushless alternator with damper windings in the main alternator and with combined ac and thyristor fed dc loads has been handled ab initio as a total modeling and simulation problem for which a complete steady state performance prediction algorithm has been developed through proper application of Park`s equivalent circuit approach individually to the main and exciter alternator units of the brushless alternator. Details of the problems faced during implementation of this algorithm through PSPICE for the case of a specific 125 kVA brushless alternator as well as methods adopted for successfully overcoming the same have then been presented. Finallymore » a comparison of the predicted performance with those obtained experimentally for this 125 kVA unit has also been provided for the cases of both thyristor fed dc load alone as well as combined ac and thyristor fed dc loads. To enable proper calculation of derating factors to be used in the design of such brushless alternators, the simulation results then include harmonic analysis of the alternator output voltage and current waveforms at the point of common connection of the ac and thyristor fed dc load, damper winding currents, main alternator field winding current, exciter alternator armature voltage and the alternator developed torque and torque angle pulsations.« less
NASA Astrophysics Data System (ADS)
Wu, Fengjun; Gao, Daqing; Shi, Chunfeng; Huang, Yuzhen; Cui, Yuan; Yan, Hongbin; Zhang, Huajian; Wang, Bin; Li, Xiaohui
2016-08-01
To solve the problems such as low input power factor, a large number of AC current harmonics and instable DC bus voltage due to the diode or thyristor rectifier used in an accelerator power supply, particularly in the Heavy Ion Research Facility in Lanzhou-Cooler Storage Ring (HIRFL-CSR), we designed and built up a new type of accelerator power supply prototype base on voltage-type space vector PWM (SVPWM) rectification technology. All the control strategies are developed in TMS320C28346, which is a digital signal processor from TI. The experimental results indicate that an accelerator power supply with a SVPWM rectifier can solve the problems above well, and the output performance such as stability, tracking error and ripple current meet the requirements of the design. The achievement of prototype confirms that applying voltage-type SVPWM rectification technology in an accelerator power supply is feasible; and it provides a good reference for design and build of this new type of power supply.
Design of high-voltage, high-power, solid state remote power controllers for aerospace applications
NASA Technical Reports Server (NTRS)
Sturman, J. C.
1985-01-01
Two general types of remote power controllers (RPC's), which combine the functions of a circuit breaker and a switch, were developed for use in dc aerospace systems. Power-switching devices used in the designs are the gate-turnoff thyristor (GTO) and MOSFET. The RPC's can switch dc voltages to 1200 V and currents to 1000 A. Seven different units were constructed and subjected to laboratory and thermal vacuum testing. Two of these were dual units that switch both positive and negative voltages simultaneously. The RPC's using MOSFET's have slow turnon and turnoff times which limit surge currents and voltage spiking from high di/dt. The GTO's have much faster transition times. All RPC's have programmable overload tripout proportional to I sq T and microsecond tripout for large overloads.
Design of high-voltage, high-power, solid state remote power controllers for aerospace applications
NASA Astrophysics Data System (ADS)
Sturman, J. C.
1985-05-01
Two general types of remote power controllers (RPC's), which combine the functions of a circuit breaker and a switch, were developed for use in dc aerospace systems. Power-switching devices used in the designs are the gate-turnoff thyristor (GTO) and MOSFET. The RPC's can switch dc voltages to 1200 V and currents to 1000 A. Seven different units were constructed and subjected to laboratory and thermal vacuum testing. Two of these were dual units that switch both positive and negative voltages simultaneously. The RPC's using MOSFET's have slow turnon and turnoff times which limit surge currents and voltage spiking from high di/dt. The GTO's have much faster transition times. All RPC's have programmable overload tripout proportional to I sq T and microsecond tripout for large overloads.
Li, Lee; Bao, Chaobing; Feng, Xibo; Liu, Yunlong; Fochan, Lin
2013-02-01
For a compact and reliable nanosecond-pulse high-voltage generator (NPHVG), the specification parameter selection and potential usage of fast controllable state-solid switches have an important bearing on the optimal design. The NPHVG with closed transformer core and fast switching thyristor (FST) was studied in this paper. According to the analysis of T-type circuit, the expressions for the voltages and currents of the primary and secondary windings on the transformer core of NPHVG were deduced, and the theoretical maximum analysis was performed. For NPHVG, the rise-rate of turn-on current (di/dt) across a FST may exceed its transient rating. Both mean and maximum values of di/dt were determined by the leakage inductances of the transformer, and the difference is 1.57 times. The optimum winding ratio is helpful to getting higher voltage output with lower specification FST, especially when the primary and secondary capacitances have been established. The oscillation period analysis can be effectively used to estimate the equivalent leakage inductance. When the core saturation effect was considered, the maximum di/dt estimated from the oscillating period of the primary current is more accurate than one from the oscillating period of the secondary voltage. Although increasing the leakage inductance of NPHVG can decrease di/dt across FST, it may reduce the output peak voltage of the NPHVG.
FET commutated current-FED inverter
NASA Technical Reports Server (NTRS)
Rippel, Wally E. (Inventor); Edwards, Dean B. (Inventor)
1983-01-01
A shunt switch comprised of a field-effect transistor (Q.sub.1) is employed to commutate a current-fed inverter (10) using thyristors (SCR1, SCR2) or bijunction transistors (Q.sub.2, Q.sub.3) in a full bridge (1, 2, 3, 4) or half bridge (5, 6) and transformer (T.sub.1) configuration. In the case of thyristors, a tapped inverter (12) is employed to couple the inverter to a dc source to back bias the thyristors during commutation. Alternatively, a commutation power supply (20) may be employed for that purpse. Diodes (D.sub.1, D.sub.2) in series with some voltage dropping element (resistor R.sub.12 or resistors R.sub.1, R.sub.2 or Zener diodes D.sub.4, D.sub.5) are connected in parallel with the thyristors in the half bridge and transformer configuration to assure sharing the back bias voltage. A clamp circuit comprised of a winding (18) negatively coupled to the inductor and a diode (D.sub.3) return stored energy from the inductor to the power supply for efficient operation with buck or boost mode.
NASA Astrophysics Data System (ADS)
Lachugin, V. F.; Panfilov, D. I.; Akhmetov, I. M.; Astashev, M. G.; Shevelev, A. V.
2014-12-01
Problems of functioning of differential current protection systems of phase shifting devices (PSD) with mechanically changed coefficient of transformation of shunt transformer are analyzed. Requirements for devices of protection of PSD with thyristor switch are formulated. Based on use of nonlinear models of series-wound and shunt transformers of PSD modes of operation of major protection during PSD, switching to zero load operation and to operation under load and during short circuit operation were studied for testing PSD with failures. Use of the principle of duplicating by devices of differential current protection (with realization of functions of breaking) of failures of separate pares of PSD with thyristor switch was substantiated. To ensure protection sensitivity to the shunt transformer winding short circuit, in particular, to a short circuit that is not implemented in the current differential protection for PSD with mechanical switch, the differential current protection reacting to the amount of primary ampere-turns of high-voltage and low-voltage winding of this transformer was designed. Studies have shown that the use of differential current cutoff instead of overcurrent protection for the shunt transformer wndings allows one to provide the sensitivity during thyristor failure with the formation of a short circuit. The results of simulation mode for the PSD with switch thyristor designed to be installed as switching point of Voskhod-Tatarskaya-Barabinsk 220 kV transmission line point out the efficiency of the developed solutions that ensure reliable functioning of the PSD.
Compact high voltage solid state switch
Glidden, Steven C.
2003-09-23
A compact, solid state, high voltage switch capable of high conduction current with a high rate of current risetime (high di/dt) that can be used to replace thyratrons in existing and new applications. The switch has multiple thyristors packaged in a single enclosure. Each thyristor has its own gate drive circuit that circuit obtains its energy from the energy that is being switched in the main circuit. The gate drives are triggered with a low voltage, low current pulse isolated by a small inexpensive transformer. The gate circuits can also be triggered with an optical signal, eliminating the trigger transformer altogether. This approach makes it easier to connect many thyristors in series to obtain the hold off voltages of greater than 80 kV.
Optimal placement of FACTS devices using optimization techniques: A review
NASA Astrophysics Data System (ADS)
Gaur, Dipesh; Mathew, Lini
2018-03-01
Modern power system is dealt with overloading problem especially transmission network which works on their maximum limit. Today’s power system network tends to become unstable and prone to collapse due to disturbances. Flexible AC Transmission system (FACTS) provides solution to problems like line overloading, voltage stability, losses, power flow etc. FACTS can play important role in improving static and dynamic performance of power system. FACTS devices need high initial investment. Therefore, FACTS location, type and their rating are vital and should be optimized to place in the network for maximum benefit. In this paper, different optimization methods like Particle Swarm Optimization (PSO), Genetic Algorithm (GA) etc. are discussed and compared for optimal location, type and rating of devices. FACTS devices such as Thyristor Controlled Series Compensator (TCSC), Static Var Compensator (SVC) and Static Synchronous Compensator (STATCOM) are considered here. Mentioned FACTS controllers effects on different IEEE bus network parameters like generation cost, active power loss, voltage stability etc. have been analyzed and compared among the devices.
Single Active Switch PV Inverter
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ramanan, V. R.; Pan, Zhiguo
This report presents a new PV inverter topology that uses only one active switch instead of 7 active switches in a conventional PV inverter. It has a buck boost converter and operates at discontinuous current control mode, which can reduce the output stage from an active switch bridge to a thyristor bridge. This concept, if successfully demonstrated, may have great cost and size/weight benefits over conventional solutions. Since the proposed topology is completely different from the traditional boost converter plus voltage source inverter approach, there is no existing control/modulation scheme available. A new modulation scheme for both the main switchmore » and the thyristors has been developed. An active clamping circuit has also been proposed to reduce switching losses and voltage spike during the switching transient. A simulation model has been set up to validate the control algorithm and clamping circuit. Simulated results show that a proposed 10 kW PV inverter can reach 5% total harmonic distortion (THD), 98.8% peak efficiency with only one main active switch, and an inductor weighing less than 3 kg. Based on that, a 10 kW prototype converter has been designed and built.« less
Integral inverter/battery charger for use in electric vehicles
NASA Technical Reports Server (NTRS)
Thimmesch, D.
1983-01-01
The design and test results of a thyristor based inverter/charger are discussed. A battery charger is included integral to the inverter by using a subset of the inverter power circuit components. The resulting charger provides electrical isolation between the vehicle propulsion battery and ac line and is capable of charging a 25 kWh propulsion battery in 8 hours from a 220 volt ac line. The integral charger employs the inverter commutation components at a resonant ac/dc isolated converter rated at 3.6 kW. Charger efficiency and power factor at an output power of 3.6 kW are 86% and 95% respectively. The inverter, when operated with a matching polyphase ac induction motor and nominal 132 volt propulsion battery, can provide a peak shaft power of 34 kW (45 ph) during motoring operation and 45 kW (60 hp) during regeneration. Thyristors are employed for the inverter power switching devices and are arranged in an input-commutated topology. This configuration requires only two thyristors to commutate the six main inverter thyristors. Inverter efficiency during motoring operation at motor shaft speeds above 450 rad/sec (4300 rpm) is 92-94% for output power levels above 11 KW (15 hp). The combined ac inverter/charger package weighs 47 kg (103 lbs).
NASA Technical Reports Server (NTRS)
Rippel, Wally E.
1990-01-01
Metal-oxide/semiconductor-controlled thyristor (MCT) and metal-oxide/semiconductor field-effect transistor (MOSFET) connected in switching circuit to obtain better performance. Offers high utilization of silicon, low forward voltage drop during "on" period of operating cycle, fast turnon and turnoff, and large turnoff safe operating area. Includes ability to operate at high temperatures, high static blocking voltage, and ease of drive.
Test SCRs and Triacs with a Lab-Built Checker
ERIC Educational Resources Information Center
Harman, Charles
2010-01-01
Students enrolled in advanced electronics courses and/or industrial electronics classes at the high school level and at technical colleges ultimately learn about solid-state switches such as the SCR (silicon controlled rectifier) and the triac. Both the SCR and the triac are in a family of four-layer devices called thyristors. They are both…
High-voltage, high-power, solid-state remote power controllers for aerospace applications
NASA Technical Reports Server (NTRS)
Sturman, J. C.
1985-01-01
Two general types of remote power controller (RPC) that combine the functions of a circuit breaker and a switch were developed for use in direct-current (dc) aerospace systems. Power-switching devices used in these designs are the relatively new gate-turnoff thyristor (GTO) and poweer metal-oxide-semiconductor field-effect transistors (MOSFET). The various RPC's can switch dc voltages to 1200 V and currents to 100 A. Seven different units were constructed and subjected to comprehensive laboratory and thermal vacuum testing. Two of these were dual units that switch both positive and negative voltages simultaneously. The RPC's using MOSFET's have slow turnon and turnoff times to limit voltage spiking from high di/dt. The GTO's have much faster transition times. All RPC's have programmable overload tripout and microsecond tripout for large overloads. The basic circuits developed can be used to build switchgear limited only by the ratings of the switching device used.
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.
Bidirectional dc-to-dc Power Converter
NASA Technical Reports Server (NTRS)
Griesbach, C. R.
1986-01-01
Solid-state, series-resonant converter uses high-voltage thyristors. Converter used either to convert high-voltage, low-current dc power to lowvoltage, high current power or reverse. Taking advantage of newly-available high-voltage thyristors to provide better reliability and efficiency than traditional converters that use vacuum tubes as power switches. New converter essentially maintenance free and provides greatly increased mean time between failures. Attractive in industrial applications whether or not bidirectional capability is required.
A Current Source Method For t(sub q) Measurement of Fast Switching Thyristors
NASA Technical Reports Server (NTRS)
Niedra, Janis M.
2006-01-01
A current source driven circuit has been constructed to measure the turn-off time (t(sub q)) of fast-switching SiC thyristors. This circuit operates from a single power supply and a dual channel pulse generator to provide adjustment of forward current, magnitude and duration of reverse applied voltage, and rate of rise of reapplied forward voltage. Values of t(sub q) down to 100 ns can be resolved.
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.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Beltran-Valle, Omar; Pena-Gallardo, Rafael; Segundo-Ramirez, Juan
This paper presents a comparative study of the application of Flexible AC Transmission System (FACTS) devices, as Thyristor Controlled Series Capacitor (TCSC), Static Synchronous Compensator (STATCOM) and Unified Power Controller (UPFC) on congestion management and voltage support in the area of the Istmo of Tehuantepec, Oaxaca, Mexico. The present work provides an analysis about the performance of the control of active and reactive power of the FACTS controllers applied to mentioned problems in the power system.
In-line Microwave Warmer for Blood and Intravenous Fluids.
1989-12-14
circuit was designed and tested. This circuit uses a digitally controlled optically coupled Triac , a thyristor device, which acts as a switch to allow...three sites of the circuit : Inlet Port of Heating Chamber Interior Path of Heating Chamber Outlet Port of Heating Chamber 4) Feedback Control Mechanism...accomplished through use of a closed loop test circuit depicted in Figure 1-2. This test circuit can be used to heat iv fluids or blood on a continuous
Design of power electronics for TVC EMA systems
NASA Technical Reports Server (NTRS)
Nelms, R. Mark
1993-01-01
The Composite Development Division of the Propulsion Laboratory at Marshall Space Flight Center (MSFC) is currently developing a class of electromechanical actuators (EMA's) for use in space transportation applications such as thrust vector control (TVC) and propellant control valves (PCV). These high power servomechanisms will require rugged, reliable, and compact power electronic modules capable of modulating several hundred amperes of current at up to 270 volts. MSFC has selected the brushless dc motor for implementation in EMA's. This report presents the results of an investigation into the applicability of two new technologies, MOS-controlled thyristors (MCT's) and pulse density modulation (PDM), to the control of brushless dc motors in EMA systems. MCT's are new power semiconductor devices, which combine the high voltage and current capabilities of conventional thyristors and the low gate drive requirements of metal oxide semiconductor field effect transistors (MOSFET's). The commanded signals in a PDM system are synthesized using a series of sinusoidal pulses instead of a series of square pulses as in a pulse width modulation (PWM) system. A resonant dc link inverter is employed to generate the sinusoidal pulses in the PDM system. This inverter permits zero-voltage switching of all semiconductors which reduces switching losses and switching stresses. The objectives of this project are to develop and validate an analytical model of the MCT device when used in high power motor control applications and to design, fabricate, and test a prototype electronic circuit employing both MCT and PDM technology for controlling a brushless dc motor.
Low-jitter high-power thyristor array pulse driver and generator
Hanks, Roy L.
2002-01-01
A method and apparatus for generating low-jitter, high-voltage and high-current pulses for driving low impedance loads such as detonator fuses uses a MOSFET driver which, when triggered, discharges a high-voltage pre-charged capacitor into the primary of a toroidal current-multiplying transformer with multiple isolated secondary windings. The secondary outputs are suitable for driving an array of thyristors that discharge a precharged high-voltage capacitor and thus generating the required high-voltage and high-current pulse.
Conceptual Study of Permanent Magnet Machine Ship Propulsion Systems
1977-12-01
cycloconverter subsystem is designed using advanced thyristors and can be either water or air cooled. The machine-cycloconverter, many-phase or parallel...Turnb, Phase, Poles, Air Gap ................................. 3-9 3-5 Machine Characteristics Versus Number of Poles (large machine, 40 000 hp). Poles...cylindrical permanent magnet generator forces the power conditioner to provide for both frequency change and voltage control. The complexity of this dual
Electric prototype power processor for a 30cm ion thruster
NASA Technical Reports Server (NTRS)
Biess, J. J.; Inouye, L. Y.; Schoenfeld, A. D.
1977-01-01
An electrical prototype power processor unit was designed, fabricated and tested with a 30 cm mercury ion engine for primary space propulsion. The power processor unit used the thyristor series resonant inverter as the basic power stage for the high power beam and discharge supplies. A transistorized series resonant inverter processed the remaining power for the low power outputs. The power processor included a digital interface unit to process all input commands and internal telemetry signals so that electric propulsion systems could be operated with a central computer system. The electrical prototype unit included design improvement in the power components such as thyristors, transistors, filters and resonant capacitors, and power transformers and inductors in order to reduce component weight, to minimize losses, and to control the component temperature rise. A design analysis for the electrical prototype is also presented on the component weight, losses, part count and reliability estimate. The electrical prototype was tested in a thermal vacuum environment. Integration tests were performed with a 30 cm ion engine and demonstrated operational compatibility. Electromagnetic interference data was also recorded on the design to provide information for spacecraft integration.
High-Speed, high-power, switching transistor
NASA Technical Reports Server (NTRS)
Carnahan, D.; Ohu, C. K.; Hower, P. L.
1979-01-01
Silicon transistor rate for 200 angstroms at 400 to 600 volts combines switching speed of transistors with ruggedness, power capacity of thyristor. Transistor introduces unique combination of increased power-handling capability, unusally low saturation and switching losses, and submicrosecond switching speeds. Potential applications include high power switching regulators, linear amplifiers, chopper controls for high frequency electrical vehicle drives, VLF transmitters, RF induction heaters, kitchen cooking ranges, and electronic scalpels for medical surgery.
Control of electromagnetic stirring by power focusing in large induction crucible furnaces
NASA Astrophysics Data System (ADS)
Frizen, V. E.; Sarapulov, F. N.
2011-12-01
An approach is proposed for the calculation of the operating conditions of an induction crucible furnace at the final stage of melting with the power focused in various regions of melted metal. The calculation is performed using a model based on the method of detailed magnetic equivalent circuits. The combination of the furnace and a thyristor frequency converter is taken into account in modeling.
Asymmetric quantum well broadband thyristor laser
NASA Astrophysics Data System (ADS)
Liu, Zhen; Wang, Jiaqi; Yu, Hongyan; Zhou, Xuliang; Chen, Weixi; Li, Zhaosong; Wang, Wei; Ding, Ying; Pan, Jiaoqing
2017-11-01
A broadband thyristor laser based on InGaAs/GaAs asymmetric quantum well (AQW) is fabricated by metal organic chemical vapor deposition (MOCVD). The 3-μm-wide Fabry-Perot (FP) ridge-waveguide laser shows an S-shape I-V characteristic and exhibits a flat-topped broadband optical spectrum coverage of ~27 nm (Δ-10 dB) at a center wavelength of ~1090 nm with a total output power of 137 mW under pulsed operation. The AQW structure was carefully designed to establish multiple energy states within, in order to broaden the gain spectrum. An obvious blue shift emission, which is not generally acquired in QW laser diodes, is observed in the broadening process of the optical spectrum as the injection current increases. This blue shift spectrum broadening is considered to result from the prominent band-filling effect enhanced by the multiple energy states of the AQW structure, as well as the optical feedback effect contributed by the thyristor laser structure. Project supported by the National Natural Science Foundation of China (Nos. 61604144, 61504137). Zhen Liu and Jiaqi Wang contributed equally to this work.
High Speed Solid State Circuit Breaker
NASA Technical Reports Server (NTRS)
Podlesak, Thomas F.
1993-01-01
The U.S. Army Research Laboratory, Fort Monmouth, NJ, has developed and is installing two 3.3 MW high speed solid state circuit breakers at the Army's Pulse Power Center. These circuit breakers will interrupt 4160V three phase power mains in no more than 300 microseconds, two orders of magnitude faster than conventional mechanical contact type circuit breakers. These circuit breakers utilize Gate Turnoff Thyristors (GTO's) and are currently utility type devices using air cooling in an air conditioned enclosure. Future refinements include liquid cooling, either water or two phase organic coolant, and more advanced semiconductors. Each of these refinements promises a more compact, more reliable unit.
Neutron, gamma ray, and temperature effects on the electrical characteristics of thyristors
NASA Technical Reports Server (NTRS)
Frasca, A. J.; Schwarze, G. E.
1992-01-01
Experimental data showing the effects of neutrons, gamma rays, and temperature on the electrical and switching characteristics of phase-control and inverter-type SCR's are presented. The special test fixture built for mounting, heating, and instrumenting the test devices is described. Four SCR's were neutron irradiated at 300 K and four at 365 K for fluences up to 3.2 x 10 exp 13 n/sq. cm, and eight were gamma irradiated at 300 K only for gamma doses up to 5.1 Mrads. The electrical measurements were made during irradiation and the switching measurements were made only before and after irradiation. Radiation induced crystal defects, resulting primarily from fast neutrons, caused the reduction of minority carrier lifetime through the generation of R-G centers. The reduction in lifetime caused increases in the on-state voltage drop and in the reverse and forward leakage currents, and decreases in the turn-off time.
Neutron, gamma ray, and temperature effects on the electrical characteristics of thyristors
NASA Technical Reports Server (NTRS)
Frasca, A. J.; Schwarze, G. E.
1992-01-01
Experimental data showing the effects of neutrons, gamma rays, and temperature on the electrical and switching characteristics of phase-control and inverter-type SCR's are presented. The special test fixture built for mounting, heating, and instrumenting the test devices is described. Four SCR's were neutron irradiated at 300 K and four at 365 K for fluences up to 3.2 x 10 exp 13 pn/sq. cm, and eight were gamma irradiated at 300 K only for gamma doses up to 5.1 Mrads. The electrical measurements were made during irradiation and the switching measurements were made only before and after irradiation. Radiation induced crystal defects, resulting primarily from fast neutrons, caused the reduction of minority carrier lifetime through the generation of R-G centers. The reduction in lifetime caused increases in the on-state voltage drop and in the reverse and forward leakage currents, and decreases in the turn-off time.
Control strategy for a variable-speed wind energy conversion system
NASA Technical Reports Server (NTRS)
Jacob, A.; Veillette, D.; Rajagopalan, V.
1979-01-01
A control concept for a variable-speed wind energy conversion system is proposed, for which a self-exited asynchronous cage generator is used along with a system of thyristor converters. The control loops are the following: (1) regulation of the entrainment speed as function of available mechanical energy by acting on the resistance couple of the asynchronous generator; (2) control of electric power delivered to the asynchronous machine, functioning as a motor, for start-up of the vertical axis wind converter; and (3) limitation of the slip value, and by consequence, of the induction currents in the presence of sudden variations of input parameters.
NASA Astrophysics Data System (ADS)
Lee, Jong-Geon; Khan, Umer Amir; Lee, Ho-Yun; Lim, Sung-Woo; Lee, Bang-Wook
2016-11-01
Commutation failure in line commutated converter based HVDC systems cause severe damages on the entire power grid system. For LCC-HVDC, thyristor valves are turned on by a firing signal but turn off control is governed by the external applied AC voltage from surrounding network. When the fault occurs in AC system, turn-off control of thyristor valves is unavailable due to the voltage collapse of point of common coupling (PCC), which causes the commutation failure in LCC-HVDC link. Due to the commutation failure, the power transfer interruption, dc voltage drop and severe voltage fluctuation in the AC system could be occurred. In a severe situation, it might cause the protection system to block the valves. In this paper, as a solution to prevent the voltage collapse on PCC and to limit the fault current, the application study of resistive superconducting fault current limiter (SFCL) on LCC-HVDC grid system was performed with mathematical and simulation analyses. The simulation model was designed by Matlab/Simulink considering Haenam-Jeju HVDC power grid in Korea which includes conventional AC system and onshore wind farm and resistive SFCL model. From the result, it was observed that the application of SFCL on LCC-HVDC system is an effective solution to mitigate the commutation failure. And then the process to determine optimum quench resistance of SFCL which enables the recovery of commutation failure was deeply investigated.
AC Resonant charger with charge rate unrelated to primary power frequency
Watson, Harold
1982-01-01
An AC resonant charger for a capacitive load, such as a PFN, is provided with a variable repetition rate unrelated to the frequency of a multi-phase AC power source by using a control unit to select and couple the phase of the power source to the resonant charger in order to charge the capacitive load with a phase that is the next to begin a half cycle. For optimum range in repetition rate and increased charging voltage, the resonant charger includes a step-up transformer and full-wave rectifier. The next phase selected may then be of either polarity, but is always selected to be of a polarity opposite the polarity of the last phase selected so that the transformer core does not saturate. Thyristors are used to select and couple the correct phase just after its zero crossover in response to a sharp pulse generated by a zero-crossover detector. The thyristor that is turned on then automatically turns off after a full half cycle of its associated phase input. A full-wave rectifier couples the secondary winding of the transformer to the load so that the load capacitance is always charged with the same polarity.
Ac resonant charger with charge rate unrelated to preimary power requency
Not Available
1979-12-07
An ac resonant charger for a capacitive load, such as a pulse forming network (PFN), is provided with a variable repetition rate unrelated to the frequency of a multi-phase ac power source by using a control unit to select and couple the phase of the power source to the resonant charger in order to charge the capacitive load with a phase that is the next to begin a half cycle. For optimum range in repetition rate and increased charging voltage, the resonant charger includes a step-up transformer and full-wave rectifier. The next phase selected may then be of either polarity, but is always selected to be of a polarity opposite the polarity of the last phase selected so that the transformer core does not saturate. Thyristors are used to select and couple the correct phase just after its zero crossover in response to a sharp pulse generated by a zero-crossover detector. The thyristor that is turned on then automatically turns off after a full half cycle of its associated phase input. A full-wave rectifier couples the secondary winding of the transformer to the load so that the load capacitance is always charged with the same polarity.
Model and Study on Cascade Control System Based on IGBT Chopping Control
NASA Astrophysics Data System (ADS)
Niu, Yuxin; Chen, Liangqiao; Wang, Shuwen
2018-01-01
Thyristor cascade control system has a wide range of applications in the industrial field, but the traditional cascade control system has some shortcomings, such as a low power factor, serious harmonic pollution. In this paper, not only analyzing its system structure and working principle, but also discussing the two main factors affecting the power factor. Chopping-control cascade control system, adopted a new power switching device IGBT, which could overcome traditional cascade control system’s two main drawbacks efficiently. The basic principle of this cascade control system is discussed in this paper and the model of speed control system is built by using MATLAB/Simulink software. Finally, the simulation results of the system shows that the system works efficiently. This system is worthy to be spread widely in engineering application.
Reliability Design for Neutron Induced Single-Event Burnout of IGBT
NASA Astrophysics Data System (ADS)
Shoji, Tomoyuki; Nishida, Shuichi; Ohnishi, Toyokazu; Fujikawa, Touma; Nose, Noboru; Hamada, Kimimori; Ishiko, Masayasu
Single-event burnout (SEB) caused by cosmic ray neutrons leads to catastrophic failures in insulated gate bipolar transistors (IGBTs). It was found experimentally that the incident neutron induced SEB failure rate increases as a function of the applied collector voltage. Moreover, the failure rate increased sharply with an increase in the applied collector voltage when the voltage exceeded a certain threshold value (SEB cutoff voltage). In this paper, transient device simulation results indicate that impact ionization at the n-drift/n+ buffer boundary is a crucially important factor in the turning-on of the parasitic pnp transistor, and eventually latch-up of the parasitic thyristor causes SEB. In addition, the device parameter dependency of the SEB cutoff voltage was analytically derived from the latch-up condition of the parasitic thyristor. As a result, it was confirmed that reducing the current gain of the parasitic transistor, such as by increasing the n-drift region thickness d was effective in increasing the SEB cutoff voltage. Furthermore, `white' neutron-irradiation experiments demonstrated that suppressing the inherent parasitic thyristor action leads to an improvement of the SEB cutoff voltage. It was confirmed that current gain optimization of the parasitic transistor is a crucial factor for establishing highly reliable design against chance failures.
Silicon controlled rectifier polyphase bridge inverter commutated with gate-turn-off thyristor
NASA Technical Reports Server (NTRS)
Edwards, Dean B. (Inventor); Rippel, Wally E. (Inventor)
1986-01-01
A polyphase SCR inverter (10) having N switching poles, each comprised of two SCR switches (1A, 1B; 2A, 2B . . . NA, NB) and two diodes (D1B; D1B; D2A, D2B . . . DNA, DNB) in series opposition with saturable reactors (L1A, L1B; L2A, L2B . . . LNA, LNB) connecting the junctions between the SCR switches and diodes to an output terminal (1, 2 . . . 3) is commutated with only one GTO thyristor (16) connected between the common negative terminal of a dc source and a tap of a series inductor (14) connected to the positive terminal of the dc source. A clamp winding (22) and diode (24) are provided, as is a snubber (18) which may have its capacitance (c) sized for maximum load current divided into a plurality of capacitors (C.sub.1, C.sub.2 . . . C.sub.N), each in series with an SCR switch S.sub.1, S.sub.2 . . . S.sub.N). The total capacitance may be selected by activating selected switches as a function of load current. A resistor 28 and SCR switch 26 shunt reverse current when the load acts as a generator, such as a motor while braking.
Digitally controlled twelve-pulse firing generator
DOE Office of Scientific and Technical Information (OSTI.GOV)
Berde, D.; Ferrara, A.A.
1981-01-01
Control System Studies for the Tokamak Fusion Test Reactor (TFTR) indicate that accurate thyristor firing in the AC-to-DC conversion system is required in order to achieve good regulation of the various field currents. Rapid update and exact firing angle control are required to avoid instabilities, large eddy currents, or parasitic oscillations. The Prototype Firing Generator was designed to satisfy these requirements. To achieve the required /plus or minus/0.77/degree/firing accuracy, a three-phase-locked loop reference was designed; otherwise, the Firing Generator employs digital circuitry. The unit, housed in a standard CAMAC crate, operates under microcomputer control. Functions are performed under program control,more » which resides in nonvolatile read-only memory. Communication with CICADA control system is provided via an 11-bit parallel interface.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
McKeever, John W; Lawler, Jack; Downing, Mark
2006-05-01
John Deere and Company (Deere), their partner, UQM Technologies, Inc. (UQM), and the Oak Ridge National Laboratory's (ORNL's) Power Electronics and Electric Machinery Research Center (PEEMRC) recently completed work on the cooperative research and development agreement (CRADA) Number ORNL 04-0691 outlined in this report. CRADA 04-0691 addresses two topical issues of interest to Deere: (1) Improved characterization of hydrogen storage and heat-transfer management; and (2) Potential benefits from advanced electric motor traction-drive technologies. This report presents the findings of the collaborative examination of potential operational and cost benefits from using ORNL/PEEMRC dual-mode inverter control (DMIC) to drive permanent magnet (PM)more » motors in applications of interest to Deere. DMIC was initially developed and patented by ORNL to enable PM motors to be driven to speeds far above base speed where the back-electromotive force (emf) equals the source voltage where it is increasingly difficult to inject current into the motor. DMIC is a modification of conventional phase advance (CPA). DMIC's dual-speed modes are below base speed, where traditional pulse-width modulation (PWM) achieves maximum torque per ampere (amp), and above base speed, where six-step operation achieves maximum power per amp. The modification that enables DMIC adds two anti-parallel thyristors in each of the three motor phases, which consequently adds the cost of six thyristors. Two features evaluated in this collaboration with potential to justify the additional thyristor cost were a possible reduction in motor cost and savings during operation because of higher efficiency, both permitted because of lower current. The collaborative analysis showed that the reduction of motor cost and base cost of the inverter was small, while the cost of adding six thyristors was greater than anticipated. Modeling the DMIC control displayed inverter efficiency gains due to reduced current, especially under light load and higher speed. This current reduction, which is the salient feature of DMIC, may be significant when operating duty cycles have low loads at high frequencies. Reduced copper losses make operation more efficient thereby reducing operating costs. In the Deere applications selected for this study, the operating benefit was overshadowed by the motor's rotational losses. Rotational losses of Deere 1 and Deere 2 dominate the overall drive efficiency so that their reduction has the greatest potential to improve performance. A good follow-up project would be to explore cost erective ways to reduce the rotational losses buy 66%. During this analysis it has been shown that, for a PM synchronous motor (PMSM), the DMIC's salient feature is its ability to minimize the current required to deliver a given power. The root-mean-square (rms) current of a motor is determined by the speed, power, motor drive parameters, and controls as I{sub rms} = (n, P, motor drive parameters, controls), where n is the relative speed, {omega}/{omega}{sub base} = {Omega}/{Omega}{sub base}, {omega} is the mechanical frequency, {Omega} is the electrical frequency, and P is the power. The characteristic current is the rms current at infinite speed, when all resistance and rotational losses are neglected. Expressions have been derived for the characteristic currents of PMSMs when the motor is controlled by CPA and by DMIC. The expression for CPA characteristic current is I{sub n{yields}{infinity}}{sup CPA} = nE{sub base}/X = nE{sub base}/n{Omega}{sub b}L = E{sub base}/{Omega}{sub b}L, which is strictly a function of the machine parameters, back-emf at base speed, base speed electrical frequency, and inductance. At high speeds, the rms current tends to remain constant even when the load-power requirements are reduced. The expression for DMIC characteristic current is I{sub n{yields}{infinity}}{sup DMIC} = P/3V{sub max} = P{pi}/3{radical}2V{sub dc}, which has nothing to do with machine parameters. This interesting result shows that at high speeds under DMIC control, the rms current diminishes as the load-power requirements are reduced. It also shows that the DMIC characteristic current can be further reduced by increasing the dc supply voltage. This explains the main benefit of DMIC; its ability to minimize the current required to meet a required load.« less
High voltage and current, gate assisted, turn-off thyristor development
NASA Technical Reports Server (NTRS)
Nowalk, T. P.; Brewster, J. B.; Kao, Y. C.
1972-01-01
An improved high speed power switch with unique turn-off capability was developed. This gate assisted turn-off thyristor (GATT) was rated 1000 volts and 100 amperes with turn-off times of 2 microseconds. Fifty units were delivered for evaluation. In addition, test circuits designed to relate to the series inverter application were built and demonstrated. In the course of this work it was determined that the basic device design is adequate to meet the static characteristics and dynamic turn-off specification. It was further determined that the turn-on specification is critically dependent on the gate drive circuit due to the distributive nature of the cathode-gate geometry. Future work should emphasize design modifications which reduce the gate current required for fast turn-on, thereby opening the way to higher power (current) devices.
Input Power Characteristics of a Three-Phase Thyristor Converter
DOT National Transportation Integrated Search
1973-10-01
A phase delay rectifier operating into a passive resistive load was instrumented in the laboratory. Techniques for accurate measurement of power, displacement reactive power, harmonic components, and distortion reactive power are presented. The chara...
An SCR inverter for electric vehicles
NASA Technical Reports Server (NTRS)
Latos, T.; Bosack, D.; Ehrlich, R.; Jahns, T.; Mezera, J.; Thimmesch, D.
1980-01-01
An inverter for an electric vehicle propulsion application has been designed and constructed to excite a polyphase induction motor from a fixed propulsion battery source. The inverter, rated at 35kW peak power, is fully regenerative and permits vehicle operation in both the forward and reverse directions. Thyristors are employed as the power switching devices arranged in a dc bus commutated topology. This paper describes the major role the controller plays in generating the motor excitation voltage and frequency to deliver performance similar to dc systems. Motoring efficiency test data for the controller are presented. It is concluded that an SCR inverter in conjunction with an ac induction motor is a viable alternative to present dc vehicle propulsion systems on the basis of performance and size criteria.
NASA Astrophysics Data System (ADS)
Ueda, Daiki; Takeuchi, Kiyoshi; Kobayashi, Masaharu; Hiramoto, Toshiro
2018-04-01
A new circuit model that provides a clear guide on designing a MOS-gated thyristor (MGT) is reported. MGT plays a significant role in achieving a steep subthreshold slope of a PN-body tied silicon-on-insulator (SOI) FET (PNBTFET), which is an SOI MOSFET merged with an MGT. The effects of design parameters on MGT and the proposed equivalent circuit model are examined to determine how to regulate the voltage response of MGT and how to suppress power dissipation. It is demonstrated that MGT with low threshold voltages, small hysteresis widths, and small power dissipation can be designed by tuning design parameters. The temperature dependence of MGT is also examined, and it is confirmed that hysteresis width decreases with the average threshold voltage kept nearly constant as temperature rises. The equivalent circuit model can be conveniently used to design low-power PNBTFET.
A 16 MJ compact pulsed power system for electromagnetic launch
NASA Astrophysics Data System (ADS)
Dai, Ling; Zhang, Qin; Zhong, Heqing; Lin, Fuchang; Li, Hua; Wang, Yan; Su, Cheng; Huang, Qinghua; Chen, Xu
2015-07-01
This paper has established a compact pulsed power system (PPS) of 16 MJ for electromagnetic rail gun. The PPS consists of pulsed forming network (PFN), chargers, monitoring system, and current junction. The PFN is composed of 156 pulse forming units (PFUs). Every PFU can be triggered simultaneously or sequentially in order to obtain different total current waveforms. The whole device except general control table is divided into two frameworks with size of 7.5 m × 2.2 m × 2.3 m. It is important to estimate the discharge current of PFU accurately for the design of the whole electromagnetic launch system. In this paper, the on-state characteristics of pulse thyristor have been researched to improve the estimation accuracy. The on-state characteristics of pulse thyristor are expressed as a logarithmic function based on experimental data. The circuit current waveform of the single PFU agrees with the simulating one. On the other hand, the coaxial discharge cable is a quick wear part in PFU because the discharge current will be up to dozens of kA even hundreds of kA. In this article, the electromagnetic field existing in the coaxial cable is calculated by finite element method. On basis of the calculation results, the structure of cable is optimized in order to improve the limit current value of the cable. At the end of the paper, the experiment current wave of the PPS with the load of rail gun is provided.
A 16 MJ compact pulsed power system for electromagnetic launch.
Dai, Ling; Zhang, Qin; Zhong, Heqing; Lin, Fuchang; Li, Hua; Wang, Yan; Su, Cheng; Huang, Qinghua; Chen, Xu
2015-07-01
This paper has established a compact pulsed power system (PPS) of 16 MJ for electromagnetic rail gun. The PPS consists of pulsed forming network (PFN), chargers, monitoring system, and current junction. The PFN is composed of 156 pulse forming units (PFUs). Every PFU can be triggered simultaneously or sequentially in order to obtain different total current waveforms. The whole device except general control table is divided into two frameworks with size of 7.5 m × 2.2 m × 2.3 m. It is important to estimate the discharge current of PFU accurately for the design of the whole electromagnetic launch system. In this paper, the on-state characteristics of pulse thyristor have been researched to improve the estimation accuracy. The on-state characteristics of pulse thyristor are expressed as a logarithmic function based on experimental data. The circuit current waveform of the single PFU agrees with the simulating one. On the other hand, the coaxial discharge cable is a quick wear part in PFU because the discharge current will be up to dozens of kA even hundreds of kA. In this article, the electromagnetic field existing in the coaxial cable is calculated by finite element method. On basis of the calculation results, the structure of cable is optimized in order to improve the limit current value of the cable. At the end of the paper, the experiment current wave of the PPS with the load of rail gun is provided.
Comparison of adaptive critic-based and classical wide-area controllers for power systems.
Ray, Swakshar; Venayagamoorthy, Ganesh Kumar; Chaudhuri, Balarko; Majumder, Rajat
2008-08-01
An adaptive critic design (ACD)-based damping controller is developed for a thyristor-controlled series capacitor (TCSC) installed in a power system with multiple poorly damped interarea modes. The performance of this ACD computational intelligence-based method is compared with two classical techniques, which are observer-based state-feedback (SF) control and linear matrix inequality LMI-H(infinity) robust control. Remote measurements are used as feedback signals to the wide-area damping controller for modulating the compensation of the TCSC. The classical methods use a linearized model of the system whereas the ACD method is purely measurement-based, leading to a nonlinear controller with fixed parameters. A comparative analysis of the controllers' performances is carried out under different disturbance scenarios. The ACD-based design has shown promising performance with very little knowledge of the system compared to classical model-based controllers. This paper also discusses the advantages and disadvantages of ACDs, SF, and LMI-H(infinity).
Extended performance electric propulsion power processor design study. Volume 2: Technical summary
NASA Technical Reports Server (NTRS)
Biess, J. J.; Inouye, L. Y.; Schoenfeld, A. D.
1977-01-01
Electric propulsion power processor technology has processed during the past decade to the point that it is considered ready for application. Several power processor design concepts were evaluated and compared. Emphasis was placed on a 30 cm ion thruster power processor with a beam power rating supply of 2.2KW to 10KW for the main propulsion power stage. Extension in power processor performance were defined and were designed in sufficient detail to determine efficiency, component weight, part count, reliability and thermal control. A detail design was performed on a microprocessor as the thyristor power processor controller. A reliability analysis was performed to evaluate the effect of the control electronics redesign. Preliminary electrical design, mechanical design and thermal analysis were performed on a 6KW power transformer for the beam supply. Bi-Mod mechanical, structural and thermal control configurations were evaluated for the power processor and preliminary estimates of mechanical weight were determined.
Design and Testing of a Small Inductive Pulsed Plasma Thruster
NASA Technical Reports Server (NTRS)
Martin, Adam K.; Dominguez, Alexandra; Eskridge, Richard H.; Polzin, Kurt A.; Riley, Daniel P.; Perdue, Kevin A.
2015-01-01
The design and testing of a small inductive pulsed plasma thruster (IPPT) is described. The device was built as a test-bed for the pulsed gas-valves and solid-state switches required for a thruster of this kind, and was designed to be modular to facilitate modification. The thruster in its present configuration consists of a multi-turn, spiral-wound acceleration coil (270 millimeters outer diameter, 100 millimeters inner diameter) driven by a 10 microfarad capacitor and switched with a high-voltage thyristor, a propellant delivery system including a fast pulsed gas-valve, and a glow-discharge pre-ionizer circuit. The acceleration coil circuit may be operated at voltages up to 4 kilovolts (the thyristor limit is 4.5 kilovolts) and the thruster operated at cyclic-rates up to 30 Herz. Initial testing of the thruster, both bench-top and in-vacuum, has been performed. Cyclic operation of the complete device was demonstrated (at 2 Herz), and a number of valuable insights pertaining to the design of these devices have been gained.
Characterization and snubbing of a bidirectional MCT in a resonant ac link converter
NASA Technical Reports Server (NTRS)
Lee, Tony; Elbuluk, Malik E.; Zinger, Donald S.
1993-01-01
The MOS-Controlled Thyristor (MCT) is emerging as a powerful switch that combines the better characteristics of existing power devices. A study of switching stresses on an MCT switch under zero voltage resonant switching is presented. The MCT is used as a bidirectional switch in an ac/ac pulse density modulated inverter for induction motor drive. Current and voltage spikes are observed and analyzed with variations in the timing of the switching. Different snubber circuit configurations are under investigation to minimize the effect of these transients. The results will be extended to study and test the MCT switching in a medium power (5 hp) induction motor drive.
Investigation of self-excited induction generators for wind turbine applications
DOE Office of Scientific and Technical Information (OSTI.GOV)
Muljadi, E.; Butterfield, C.P.; Sallan, J.
2000-02-28
The use of squirrel-cage induction machines in wind generation is widely accepted as a generator of choice. The squirrel-cage induction machine is simple, reliable, cheap, lightweight, and requires very little maintenance. Generally, the induction generator is connected to the utility at constant frequency. With a constant frequency operation, the induction generator operates at practically constant speed (small range of slip). The wind turbine operates in optimum efficiency only within a small range of wind speed variation. The variable-speed operation allows an increase in energy captured and reduces both the torque peaks in the drive train and the power fluctuations sentmore » to the utility. In variable-speed operation, an induction generator needs an interface to convert the variable frequency output of the generator to the fixed frequency at the utility. This interface can be simplified by using a self-excited generator because a simple diode bridge is required to perform the ac/dc conversion. The subsequent dc/ac conversion can be performed using different techniques. The use of a thyristor bridge is readily available for large power conversion and has a lower cost and higher reliability. The firing angle of the inverter bridge can be controlled to track the optimum power curve of the wind turbine. With only diodes and thyristors used in power conversion, the system can be scaled up to a very high voltage and high power applications. This paper analyzes the operation of such a system applied to a 1/3-hp self-excited induction generator. It includes the simulations and tests performed for the different excitation configurations.« less
2006-12-31
Reset (Write a Ŕ") * Apply current to melt memory element * Cool quickly to " freeze -in" amorphous state * Amorphous state = high resistance = low...It consists of a 6 jtF storage capacitor switched by 3 series thyristors. The module output is connected to the x-ray source through a ferrite
Specifics of Pulsed Arc Welding Power Supply Performance Based On A Transistor Switch
NASA Astrophysics Data System (ADS)
Krampit, N. Yu; Kust, T. S.; Krampit, M. A.
2016-08-01
Specifics of designing a pulsed arc welding power supply device are presented in the paper. Electronic components for managing large current was analyzed. Strengths and shortcomings of power supply circuits based on thyristor, bipolar transistor and MOSFET are outlined. As a base unit for pulsed arc welding was chosen MOSFET transistor, which is easy to manage. Measures to protect a transistor are given. As for the transistor control device is a microcontroller Arduino which has a low cost and adequate performance of the work. Bead transfer principle is to change the voltage on the arc in the formation of beads on the wire end. Microcontroller controls transistor when the arc voltage reaches the threshold voltage. Thus there is a separation and transfer of beads without splashing. Control strategies tested on a real device and presented. The error in the operation of the device is less than 25 us, it can be used controlling drop transfer at high frequencies (up to 1300 Hz).
EVA Metro Sedan electric-propulsion system: test and evaluation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Reimers, E.
1979-09-01
The procedure and results of the performance evaluation of the EVA Metro Sedan (car No. 1) variable speed dc chopper motor drive and its three speed automatic transmission are presented. The propulsion system for a battery powered vehicle manufactured by Electric Vehicle Associates, Valley View, Ohio, was removed from the vehicle, mounted on the programmable electric dynamometer test facility and evaluated with the aid of a hp 3052A Data Acquisition System. Performance data for the automatic transmission, the solid state dc motor speed controller, and the dc motor in the continuous and pulsating dc power mode, as derived on themore » dynamometer test facility, as well as the entire propulsion system are given. This concept and the system's components were evaluated in terms of commercial applicability, maintainability, and energy utility to establish a design base for the further development of this system or similar propulsion drives. The propulsion system of the EVA Metro Sedan is powered by sixteen 6-volt traction batteries, Type EV 106 (Exide Battery Mfg. Co.). A thyristor controlled cable form Pulsomatic Mark 10 controller, actuated by a foot throttle, controls the voltage applied to a dc series field motor, rated at 10 hp at 3800 rpm (Baldor Electric Co.). Gear speed reduction to the wheel is accomplished by the original equipment three speed automatic transmission with torque converter (Renault 12 Sedan). The brake consists of a power-assisted, hydraulic braking system with front wheel disk and rear drum. An ability to recuperate electric energy with subsequent storage in the battery power supply is not provided.« less
Safe Distances From a High-Energy Capacitor Bank for Ear and Lung Protection
2014-06-01
switching network or device such as a Silicon Carbide Gate Turn-Off Thyristor (SGTO), Pulse Forming Network (PFN), Gas Tube, Traveling Wave Tube...increase in pressure produces an imbalance of pressure in the body and causes injury. As an example, the eardrum membrane may break if the outside
A study of DC-DC converters with MCT's for arcjet power supplies
NASA Technical Reports Server (NTRS)
Stuart, Thomas A.
1994-01-01
Many arcjet DC power supplies use PWM full bridge converters with large arrays of parallel FET's. This report investigates an alternative supply using a variable frequency series resonant converter with small arrays of parallel MCT's (metal oxide semiconductor controlled thyristors). The reasons for this approach are to: increase reliability by reducing the number of switching devices; and decrease the surface mounting area of the switching arrays. The variable frequency series resonant approach is used because the relatively slow switching speed of the MCT precludes the use of PWM. The 10 kW converter operated satisfactorily with an efficiency of over 91 percent. Test results indicate this efficiency could be increased further by additional optimization of the series resonant inductor.
20 T portable bipolar magnetic pulser.
Wolf Cruz, R R; Dias, A L B; Bonfim, M J C
2010-06-01
High magnetic fields are required for the study of hard magnetic materials and, in many cases, the reversal of these fields is essential. This paper describes a portable pulse generator capable of producing bipolar magnetic fields up to 20 T into a copper coil. The peak current around 7 kA is achieved by discharging two capacitor banks through a combination of thyristors and fast diodes. Each pulse polarity has a semisinusoidal shape with 18 mus base width. Pulse triggering is computer controlled and magnetic measurements are done by an induction coil or Kerr effect acquired by a sampling oscilloscope. The whole apparatus weighs less than 2 kg. Hysteresis loops of NdFeB magnets were done to demonstrate the viability of the system.
Su, Gui-Jia
2003-06-10
A multilevel DC link inverter and method for improving torque response and current regulation in permanent magnet motors and switched reluctance motors having a low inductance includes a plurality of voltage controlled cells connected in series for applying a resulting dc voltage comprised of one or more incremental dc voltages. The cells are provided with switches for increasing the resulting applied dc voltage as speed and back EMF increase, while limiting the voltage that is applied to the commutation switches to perform PWM or dc voltage stepping functions, so as to limit current ripple in the stator windings below an acceptable level, typically 5%. Several embodiments are disclosed including inverters using IGBT's, inverters using thyristors. All of the inverters are operable in both motoring and regenerating modes.
NASA Astrophysics Data System (ADS)
Roy, Pinku; Maiti, Tanmoy
2018-02-01
Double perovskite materials have been studied in detail by many researchers, as their magnetic and electronic properties can be controlled by the substitution of alkaline earth metals or lanthanides in the A site and transition metals in the B site. Here we report the temperature-driven, p-n-type conduction switching assisted, large change in thermopower in La3+-doped Sr2TiFeO6-based double perovskites. Stoichiometric compositions of La x Sr2-x TiFeO6 (LSTF) with 0 ⩽ x ⩽ 0.25 were synthesized by the solid-state reaction method. Rietveld refinement of room-temperature XRD data confirmed a single-phase solid solution with cubic crystal structure and Pm\\bar{3}m space group. From temperature-dependent electrical conductivity and Seebeck coefficient (S) studies it is evident that all the compositions underwent an intermediate semiconductor-to-metal transition before the semiconductor phase reappeared at higher temperature. In the process of semiconductor-metal-semiconductor transition, LSTF compositions demonstrated temperature-driven p-n-type conduction switching behavior. The electronic restructuring which occurs due to the intermediate metallic phase between semiconductor phases leads to the colossal change in S for LSTF oxides. The maximum drop in thermopower (ΔS ~ 2516 µV K-1) was observed for LSTF with x = 0.1 composition. Owing to their enormous change in thermopower of the order of millivolts per kelvin, integrated with p-n-type resistance switching, these double perovskites can be used for various high-temperature multifunctional device applications such as diodes, sensors, switches, thermistors, thyristors, thermal runaway monitors etc. Furthermore, the conduction mechanisms of these oxides were explained by the small polaron hopping model.
NASA Astrophysics Data System (ADS)
Kim, Sung-Kyu; Kim, Kwangmin; Park, Minwon; Yu, In-Keun; Lee, Sangjin
2015-11-01
High temperature superconducting (HTS) devices are being developed due to their advantages. Most line commutated converter based high voltage direct current (HVDC) transmission systems for long-distance transmission require large inductance of DC reactor; however, generally, copper-based reactors cause a lot of electrical losses during the system operation. This is driving researchers to develop a new type of DC reactor using HTS wire. The authors have developed a 400 mH class HTS DC reactor and a laboratory scale test-bed for line-commutated converter type HVDC system and applied the HTS DC reactor to the HVDC system to investigate their operating characteristics. The 400 mH class HTS DC reactor is designed using a toroid type magnet. The HVDC system is designed in the form of a mono-pole system with thyristor-based 12-pulse power converters. In this paper, the investigation results of the HTS DC reactor in connection with the HVDC system are described. The operating characteristics of the HTS DC reactor are analyzed under various operating conditions of the system. Through the results, applicability of an HTS DC reactor in an HVDC system is discussed in detail.
NASA Astrophysics Data System (ADS)
Steigerwald, R. L.; Ferraro, A.; Turnbull, F. G.
1983-04-01
Power conditioning systems that interface with photovoltaic arrays are presently investigated for the cases of 5-30 kW residential systems interfacing with a 240-V single-phase utility connection, and 30-200 kW intermediate systems interfacing with a 480-V three-phase utility connection. Both systems require an isolation transformer between the array and the utility interface. A tradeoff study is conducted for numerous transistor and thyristor circuits and configurations, with weighting criteria that include full- and part-load efficiency, size, weight, reliability, ease of control, injected harmonics, reactive power requirements, and parts cost. On the basis of study results, a 10-kW high frequency transistor inverter feeding a high frequency isolation transformer with a sinusoidally shaped current wave was selected.
NASA Astrophysics Data System (ADS)
Jiang, Yanfeng; Zhang, Changnian; Zhang, Xiaobo
2005-02-01
In this paper, a novel method for fabricating a static induction thyristor has been put forward, using silicon direct bonding instead of traditional epitaxy during the construction of a cathode. Thus, an obvious improvement of the breakdown value of gate-cathode junction has been observed and consequently the gate controllability on anode voltage has been enhanced. The bonded interface has been studied. Some adjustments in technology have been adopted to enhance the bonding quality. A way to guarantee the consistency of the breakdown voltage of gate junction with respect to the cathode has been advanced. Some measurements of I-V characteristic of SDB-SITH have been carried out and the practical result is also listed. A comparison between the SDB-SITH and epitaxial SITH has been made, mainly on I-V and the switching time.
High-voltage, high-current, solid-state closing switch
DOE Office of Scientific and Technical Information (OSTI.GOV)
Focia, Ronald Jeffrey
2017-08-22
A high-voltage, high-current, solid-state closing switch uses a field-effect transistor (e.g., a MOSFET) to trigger a high-voltage stack of thyristors. The switch can have a high hold-off voltage, high current carrying capacity, and high time-rate-of-change of current, di/dt. The fast closing switch can be used in pulsed power applications.
100-kA vacuum current breaker of a modular design
NASA Astrophysics Data System (ADS)
Ivanov, V. P.; Vozdvijenskii, V. A.; Jagnov, V. A.; Solodovnikov, S. G.; Mazulin, A. V.; Ryjkov, V. M.
1994-05-01
Direct current breaker of a modular design is developed for the strong field tokamak power supply system. The power supply system comprises four 800 MW alternative current generators with 4 GJ flywheels, thyristor rectifiers providing inductive stores pumping by a current up to 100 kA for 1 - 4 sec. To form current pulses of various shapes in the tokamak windings current breakers are used with either pneumatic or explosive drive, at a current switching synchronously of not worse than 100 mks. Current breakers of these types require that the current conducting elements be replaced after each shot. For recent years vacuum arc quenching chambers with an axial magnetic field are successfully employed as repetitive performance current breakers, basically for currents up to 40 kA. In the report some results of researches of a vacuum switch modular are presented which we used as prototype switch for currents of the order of 100 kA.
A Preliminary Cost Study of the Dual Mode Inverter Controller
DOE Office of Scientific and Technical Information (OSTI.GOV)
McKeever, J.W.
2005-01-28
In 1998, the Power Electronics and Electric Machinery Research Center (PEEMRC) at the Oak Ridge National Laboratory (ORNL) started a program to investigate alternate field weakening schemes for permanent magnet (PM) motors. The adjective ''alternate'' was used because at that time, outside research emphasis was on motors with interior-mounted PMs (IPMs). The PEEMRC emphasis was placed on motors with surface-mounted PMs (SPMs) because of the relative ease of manufacturing SPM motors compared with the IPM motors. Today the PEEMRC is continuing research on SPMs while examining the IPMs that have been developed by industry. Out of this task--the goal ofmore » which was to find ways to drive PM motors that inherently have low inductance at high speeds where their back-emf exceeds the supply voltage--ORNL developed and demonstrated the dual mode inverter control (DMIC) [1,2] method of field weakening for SPM motors. The predecessor of DMIC is conventional phase advance (CPA), which was developed by UQM Technologies, Inc. [3]. Fig. 1 shows the three sets of anti-parallel thyristors in the dashed box that comprise the DMIC. If one removes the dashed box by shorting each set of anti-parallel thyristors, the configuration becomes a conventional full bridge inverter on the left driving a three phase motor on the right. CPA may be used to drive this configuration ORNL's initial analyses of CPA and DMIC were based on driving motors with trapezoidal back-emfs [4-6], obtained using double layer lapped stator windings with one slot per pole per phase. A PM motor with a sinusoidal back-emf obtained with two poles per slot per phase has been analyzed under DMIC operation as a University of Tennessee-Knoxville (UTK) doctoral dissertation [7]. In the process of this research, ORNL has completed an analysis that explains and quantifies the role of inductance in these methods of control. The Appendix includes information on the equations for the three components of phase inductance, L{sub gap}, L{sub slot}, and L{sub endturns}. PM motors inherently have a lower inductance because of the increase in effective air gap caused by the magnet, which is in the denominator of the equation for L{sub gap}. L{sub gap} accounts for about half of the phase inductance. Because of the low inductance, there is a propensity for currents to exceed the motor's rated value. DMIC solves this problem for low-inductance PM motors and, in addition, provides a number of safety features that protect against uncontrolled generator mode operation [8,9]; however, the DMIC topology adds a pair of anti-parallel thyristors in each of the three phases, thereby introducing additional silicon costs as well as additional voltage drops during operation. It poses the tradeoff question; under what conditions can the beneficial features of DMIC offset its additional silicon cost and voltage drop losses? The purpose of this report is to address the tradeoff question. Sections of the report will: (1) review the role of self-inductance in performance and control of PM motors, (2) discuss the bounding inductances for motors with trapezoidal back-emfs under CPA control, (3) discuss the bounding inductances for trapezoidal back-emfs under DMIC, (4) discuss the bounding inductances for the PM synchronous motor (PMSM), (5) present the analysis showing how DMIC minimizes current in PMSMs, (6) present the results of a cost study conducted for two motors driven using a CPA inverter and for two motors driven using DMIC, (7) discuss estimating life cycle cost benefits, and (8) present conclusions.« less
USSR and Eastern Europe Scientific Abstracts, Electronics and Electrical Engineering, Number 27
1977-02-10
input and output conditions. The power section of the circuit is modified to permit triacs and thyristors, respectively, to function. The purpose of the...electronic materials, components, and devices, on circuit theory, pulse techniques, electromagnetic wave propagation, radar, quantum electronic theory...Lasers, Masers, Holography, Quasi-Optical 20 Microelectronics and General Circuit Theory and Information 21 Radars and Radio Wavigati on 22
TCSC based filtering and improvement of power quality
NASA Astrophysics Data System (ADS)
Arulvendhan, K.; Dilli srinivasan, J.; Vinil, M.
2018-04-01
Thyristor Controlled Series Capacitor (TCSC) as a dynamic system, also its competence in growing power allocation in transmission lines, can be used to improve different power system problems. TCSC’s dissimilar advantages can be categorised as steady-state and transient ones. During a fault, TCSC can increase power quality by reducing the current and benefit to keep the voltage as high as conceivable. In this paper, the application of TCSC to enrich one of the vital power quality issues, i.e., voltage sag is investigated. Different operating modes of TCSC have dissimilar influences on the voltage of the bus that the line armed with TCSC is connected to. Relocating to bypass mode upon manifestation of a fault is a significant feature of TCSC to advance voltage sag. The simulations on a trial network disclose these facts.
Electric drive motors for industrial robots
NASA Astrophysics Data System (ADS)
Fichtner, K.
1985-04-01
In robotized industrial plants it is possible to use electric motors in the technological process and also for control, assembly, transport, testing, and measurements. Particularly suitable for these applications are permanent-magnet d.c. motors. A new special series was developed for industrial robots with hinge joints in kinematic pairs. The complete drive includes thyristors or transistor controls with regulators and, if necessary, a line transformer as well as a servomotor with tachometer and odometer for speed, current, and position control. The drive is coupled to a robot tong through mechanical torque and force converters. In addition to a 0 to 4000 rpm speed regulation, without wobble at low speeds, and a high torque-to-weight ratio for repetitive short-time heavy duty, these low-inertia motors develop high starting and accelerating torques over the entire speed range. They operate from a 1 to O 220 V a.c. line through a rectifier. The motors are totally enclosed, or of open construction for better ventilation. Their windings have class F insulation for operation at ambient temperatures up to 40 C.
Finite Element Method Applied to Fuse Protection Design
NASA Astrophysics Data System (ADS)
Li, Sen; Song, Zhiquan; Zhang, Ming; Xu, Liuwei; Li, Jinchao; Fu, Peng; Wang, Min; Dong, Lin
2014-03-01
In a poloidal field (PF) converter module, fuse protection is of great importance to ensure the safety of the thyristors. The fuse is pre-selected in a traditional way and then verified by finite element analysis. A 3D physical model is built by ANSYS software to solve the thermal-electric coupled problem of transient process in case of external fault. The result shows that this method is feasible.
Sakudo, Akikazu; Toyokawa, Yoichi; Imanishi, Yuichiro
2016-01-01
Adenovirus is one of the most important causative agents of iatrogenic infections derived from contaminated medical devices or finger contact. In this study, we investigated whether nitrogen gas plasma, generated by applying a short high-voltage pulse to nitrogen using a static induction thyristor power supply (1.5 kilo pulse per second), exhibited a virucidal effect against adenoviruses. Viral titer was reduced by one log within 0.94 min. Results from detection of viral capsid proteins, hexon and penton, by Western blotting and immunochromatography were unaffected by the plasma treatment. In contrast, analysis using the polymerase chain reaction suggested that plasma treatment damages the viral genomic DNA. Reactive chemical products (hydrogen peroxide, nitrate, and nitrite), ultraviolet light (UV-A) and slight temperature elevations were observed during the operation of the gas plasma device. Viral titer versus intensity of each potential virucidal factor were used to identify the primary mechanism of disinfection of adenovirus. Although exposure to equivalent levels of UV-A or heat treatment did not inactivate adenovirus, treatment with a relatively low concentration of hydrogen peroxide efficiently inactivated the virus. Our results suggest the nitrogen gas plasma generates reactive chemical products that inactivate adenovirus by damaging the viral genomic DNA. PMID:27322066
NASA Astrophysics Data System (ADS)
Shestakov, E. A.; Savrukhin, P. V.
2017-10-01
Experiments in the T-10 tokamak demonstrated possibility of controlling the plasma current during disruption instability using the electron cyclotron resonance heating (ECRH) and the controlled operation of the ohmic current-holding system. Quasistable plasma discharge with repeating sawtooth oscillations can be restored after energy quench using auxiliary ECRH power when PEC / POH > 2-5. The external magnetic field generation system consisted of eight saddle coils that were arranged symmetrically relative to the equatorial plane of the torus outside of the vacuum vessel of the T-10 tokamak to study the possible resonant magnetic field effects on the rotation frequency of magnetic islands. The saddle coils power supply system is based on four thyristor converters with a total power of 300 kW. The power supply control system is based on Siemens S7 controllers. As shown by preliminary experiments, the interaction efficiency of external magnetic fields with plasma depends on the plasma magnetic configuration. Optimal conditions for slowing the rotation of magnetic islands were determined. Additionally, the direction of the error magnetic field in the T-10 tokamak was determined, and the threshold value of the external magnetic field was determined.
Hybrid inverter for HVDC/weak AC system interconnection
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tam, K.S.
1985-01-01
The concept of the hybrid converter is introduced. By independently controlling a naturally commutated converter (NCC) and an artificially commutated converter (ACC), real power and reactive power can be controlled independently. Alternatively, the ac bus voltage can be regulated without affecting the real power transfer. Independent control is feasible only within certain operating boundaries. Twelve pulse operation, sequential control, and complementary circuits may be viewed as variations of the hybrid converter. The concept of the hybrid converter is demonstrated by digital simulation. At the current state of technology, the NCC is best implemented by a 6-pulse bridge using thyristors asmore » the switching elements. A survey of power electronics applicable to HVDC applications reveals that the capacitively commutated current-sourced converters are either technically or economically better than the other alternatives for the implementation of the ACC. The digital simulation results show that the problems of operating an HVDC system into a weak ac system can be solved by using a hybrid inverter. A new control scheme, the zero Q control, is developed. With no reactive power interaction between the dc system and the ac system, the stability of the HVDC/weak ac system operation is significantly improved. System start-up and fault recovery is fast and stable.« less
Component technology for space power systems
NASA Technical Reports Server (NTRS)
Finke, R.
1982-01-01
The Lewis/OAST program for the development of Component Technology for Space Power Systems is described. The program is divided into five generic areas: semiconductor devices (transistors, thyristors, and diodes); conductors (materials and transmission lines); dielectrics; magnetic devices; and thermal control devices. Examples of progress in each of the five areas is discussed. Bipolar power transistors up to 1000 V at 100 A with a gain of 10 and a 0.5 mu sec rise and fall time are presented. A new class of semiconductor devices with a possibility of switching 1000 000 V is described. Several 100 kW rotary power transformer designs and a 25 kW, 20 kHz transformer weighting 3.2 kg have been developed. Progress on the creation of diamond-like films for thermal devices and intercalated carbon fibers with the strength of steel and the conductivity of copper at one third the mass of copper is presented.
Electrical Textile Valves for Paper Microfluidics.
Ainla, Alar; Hamedi, Mahiar M; Güder, Firat; Whitesides, George M
2017-10-01
This paper describes electrically-activated fluidic valves that operate based on electrowetting through textiles. The valves are fabricated from electrically conductive, insulated, hydrophobic textiles, but the concept can be extended to other porous materials. When the valve is closed, the liquid cannot pass through the hydrophobic textile. Upon application of a potential (in the range of 100-1000 V) between the textile and the liquid, the valve opens and the liquid penetrates the textile. These valves actuate in less than 1 s, require low energy (≈27 µJ per actuation), and work with a variety of aqueous solutions, including those with low surface tension and those containing bioanalytes. They are bistable in function, and are, in a sense, the electrofluidic analog of thyristors. They can be integrated into paper microfluidic devices to make circuits that are capable of controlling liquid, including autonomous fluidic timers and fluidic logic. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
NASA Astrophysics Data System (ADS)
Apribowo, Chico Hermanu Brillianto; Ibrahim, Muhammad Hamka; Wicaksono, F. X. Rian
2018-02-01
The growing burden of the load and the complexity of the power system has had an impact on the need for optimization of power system operation. Optimal power flow (OPF) with optimal location placement and rating of thyristor controlled series capacitor (TCSC) is an effective solution used to determine the economic cost of operating the plant and regulate the power flow in the power system. The purpose of this study is to minimize the total cost of generation by placing the location and the optimal rating of TCSC using genetic algorithm-design of experiment techniques (GA-DOE). Simulation on Java-Bali system 500 kV with the amount of TCSC used by 5 compensator, the proposed method can reduce the generation cost by 0.89% compared to OPF without using TCSC.
Electric vehicle energy management system
NASA Astrophysics Data System (ADS)
Alaoui, Chakib
This thesis investigates and analyzes novel strategies for the optimum energy management of electric vehicles (EVs). These are aimed to maximize the useful life of the EV batteries and make the EV more practical in order to increase its acceptability to market. The first strategy concerns the right choice of the batteries for the EV according to the user's driving habits, which may vary. Tests conducted at the University of Massachusetts Lowell battery lab show that the batteries perform differently from one manufacturer to the other. The second strategy was to investigate the fast chargeability of different batteries, which leads to reduce the time needed to recharge the EV battery pack. Tests were conducted again to prove that only few battery types could be fast charged. Test data were used to design a fast battery charger that could be installed in an EV charging station. The third strategy was the design, fabrication and application of an Electric Vehicle Diagnostic and Rejuvenation System (EVDRS). This system is based on Mosfet Controlled Thyristors (MCTs). It is capable of quickly identifying any failing battery(s) within the EV pack and rejuvenating the whole battery pack without dismantling them and unloading them. A novel algorithm to rejuvenate Electric Vehicle Sealed Lead Acid Batteries is described. This rejuvenation extends the useful life of the batteries and makes the EV more competitive. The fourth strategy was to design a thermal management system for EV, which is crucial to the safe operation, and the achievement of normal/optimal performance of, electric vehicle (EV) batteries. A novel approach for EV thermal management, based on Pettier-Effect heat pumps, was designed, fabricated and tested in EV. It shows the application of this type of technology for thermal management of EVs.
Advanced AC permanent magnet axial flux disc motor for electric passenger vehicle
NASA Technical Reports Server (NTRS)
Kliman, G. B.
1982-01-01
An ac permanent magnet axial flux disc motor was developed to operate with a thyristor load commutated inverter as part of an electric vehicle drive system. The motor was required to deliver 29.8 kW (40 hp) peak and 10.4 kW (14 hp) average with a maximum speed of 11,000 rpm. It was also required to run at leading power factor to commutate the inverter. Three motors were built.
Inverter for interfacing advanced energy sources to a utility grid
Steigerwald, Robert L.
1984-01-01
A transistor is operated in the PWM mode such that a hlaf sine wave of current is delivered first to one-half of a distribution transformer and then the other as determined by steering thyristors operated at the fundamental sinusoidal frequency. Power to the transistor is supplied by a dc source such as a solar array and the power is converted such that a sinusoidal current is injected into a utility at near unity power factor.
1983-04-01
34.. .. . ...- "- -,-. SIGNIFICANCE AND EXPLANATION Many different codes for the simulation of semiconductor devices such as transitors , diodes, thyristors are already circulated...partially take into account the consequences introduced by degenerate semiconductors (e.g. invalidity of Boltzmann’s statistics , bandgap narrowing). These...ft - ni p nep /Ut(2.10) Sni *e p nie 2.11) .7. (2.10) can be physically interpreted as the application of Boltzmann statistics . However (2.10) a.,zo
Minority Carrier Lifetimes in Halide Chemical Vapor Deposition SiC
2006-06-01
less efficient than IGBTs , or thyristors. In other words, with the increase of blocking voltage, bipolar devices are preferred. The on-state losses...was inductively heated by a 50 kW generator operating at the frequency of approximately 10 kHz. The HCVD reaction zone is similar in shape and...C, the furnace was backfilled with argon to the pressure of 600 Torr and the temperature was increased slowly to the growth temperature. Growth
NASA Astrophysics Data System (ADS)
Tokuchi, Akira; Kamitsukasa, Fumiyoshi; Furukawa, Kazuya; Kawase, Keigo; Kato, Ryukou; Irizawa, Akinori; Fujimoto, Masaki; Osumi, Hiroki; Funakoshi, Sousuke; Tsutsumi, Ryouta; Suemine, Shoji; Honda, Yoshihide; Isoyama, Goro
2015-01-01
We developed a solid-state switch with static induction thyristors for the klystron modulator of the L-band electron linear accelerator (linac) at the Institute of Scientific and Industrial Research, Osaka University. This switch is designed to have maximum specifications of a holding voltage of 25 kV and a current of 6 kA at the repetition frequency of 10 Hz for forced air cooling. The turn-on time of the switch was measured with a matched resistor to be 270 ns, which is sufficiently fast for the klystron modulator. The switch is retrofitted in the modulator to generate 1.3 GHz RF pulses with durations of either 4 or 8 μs using a 30 MW klystron, and the linac is successfully operated under maximum conditions. This finding demonstrates that the switch can be used as a high-power switch for the modulator. Pulse-to-pulse variations of the klystron voltage are measured to be less than 0.015%, and those of RF power and phase are lower than 0.15% and 0.1°, respectively. These values are significantly smaller than those obtained with a thyratron; hence, the stability of the main RF system is improved. The solid-state switch has been used in normal operation of the linac for more than a year without any serious trouble. Thus, we confirmed the switch's robustness and long-term reliability.
Silicon device performance measurements to support temperature range enhancement
NASA Technical Reports Server (NTRS)
Bromstead, James; Weir, Bennett; Johnson, R. Wayne; Askew, Ray
1992-01-01
Testing of the metal oxide semiconductor (MOS)-controlled thyristor (MCT) has uncovered a failure mechanism at elevated temperature. The failure appears to be due to breakdown of the gate oxide. Further testing is underway to verify the failure mode. Higher current level inverters were built to demonstrate 200 C operation of the N-MOSFET's and insulated-gate-bipolar transistors (IGBT's) and for life testing. One MOSFET failed early in testing. The origin of this failure is being studied. No IGBT's have failed. A prototype 28-to-42 V converter was built and is being tested at room temperature. The control loop is being finalized. Temperature stable, high value (10 micro-F) capacitors appear to be the limiting factor in the design at this time. In this application, the efficiency will be lower for the IGBT version due to the large V sub(cesat) (3.5-4 V) compared to the input voltage of 28 V. The MOSFET version should have higher efficiency; however, the MOSFET does not appear to be as robust at 200 C. Both versions are built for comparison.
Design and fabrication of GaAs OMIST photodetector
NASA Astrophysics Data System (ADS)
Kang, Xuejun; Lin, ShiMing; Liao, Qiwei; Gao, Junhua; Liu, Shi'an; Cheng, Peng; Wang, Hongjie; Zhang, Chunhui; Wang, Qiming
1998-08-01
We designed and fabricated GaAs OMIST (Optical-controlled Metal-Insulator-Semiconductor Thyristor) device. Using oxidation of AlAs layer that is grown by MBE forms the Ultra- Thin semi-Insulating layer (UTI) of the GAAS OMIST. The accurate control and formation of high quality semi-insulating layer (AlxOy) are the key processes for fabricating GaAs OMIST. The device exhibits a current-controlled negative resistance region in its I-V characteristics. When illuminated, the major effect of optical excitation is the reduction of the switching voltage. If the GaAs OMIST device is biased at a voltage below its dark switching voltage Vs, sufficient incident light can switch OMIST from high impedance low current 'off' state to low impedance high current 'on' state. The absorbing material of OMIST is GaAS, so if the wavelength of incident light within 600 to approximately 850 nm can be detected effectively. It is suitable to be used as photodetector for digital optical data process. The other attractive features of GaAs OMIST device include suitable conducted current, switching voltage and power levels for OEIC, high switch speed and high sensitivity to light or current injection.
11.72 sq cm SiC Wafer-scale Interconnected 64 kA PiN Diode
2012-01-30
drop of 10.3 V. The dissipated energy was 382 J and the calculated action exceeded 1.7 MA2 -s. Preliminary development of high voltage interconnection...scale diode action (surge current integral), a key reliability parameter, exceeded 1.7 MA2 -s. Figure 6: The wafer-scale interconnected diode...scale diode was 382 J and the calculated action exceeded 1.7 MA2 -sec. High voltage operation of PiN diodes, thyristors, and other semiconductor
2016-06-01
inch gun on impact [1]. The potential of the EM railgun renders the need to store dangerous explosives associated with the conventional warheads...leaves the gun . The simulation will outline some critical performance characteristics of a buck-boost power supply as compared to a thyristor-based...between the rails and from the projectile position along the length of the gun x [5]: 3 1 2 2 2 w o
2006-08-01
semiconductor (nMOS) and turned it off through a positive metal oxide semiconductor (pMOS). For turn-on, although 1 V worked, a HP6227B power supply at 2...E3614A power supply at –8 V provided IG during the rise time, and thus need enough capacitance working to a frequency around 3/trise time...load’s screw terminal posts would have reduced the ESL and ESR. The SGTO turned off 5.8 A from the power supply at 20 V and was usually fan cooled
NASA Astrophysics Data System (ADS)
Xu, Kaili
Wyoming is by far the largest coal producing state in the US, but local utilization is extremely low. As much as 92% of Wyoming's coal is shipped to the other states and is mainly consumed by their electricity producers. Coal accounts for more than 50% of the US electricity generation and is one of the least expensive energy sources. Wyoming could utilize its coal better by exporting electricity instead of exporting the coal only in its raw form. Natural gas is another important energy resource in Wyoming but local utilization is even lower. As a result of the development in coalbed methane fields, natural gas production in Wyoming is almost in pace with its coal production. In addition to constructing more new pipelines, new transmission lines should be considered as an alternative way of exporting this energy. Because of their enormous electricity market sizes and high electricity prices, California, Texas and Illinois are chosen to be the target markets for Wyoming's electricity. The proposed transmission schemes use High Voltage DC (HVDC) lines, which are suitable for long distance and cross-system power transmission. Technical and economic feasibilities are studied in details. The Wyoming-California scheme has a better return of investment than both the Wyoming-Texas and the Wyoming-Illinois schemes. A major drawback of HVDC transmission is the high level of harmonics generated by the converters. Elaborate filtering is required at both the AC and the DC sides. A novel pulse-multiplication method is proposed in the thesis to reduce the harmonics from the converter source. By introducing an averaging inductor, the proposed method uses less thyristors to achieve the same high-pulse operation as the existing series scheme. The reduction of thyristors makes the switching circuit more reliable and easier to control and maintain. Harmonic analysis shows that the harmonic level can be reduced to about one third of the original system. The proposed method is also simulated by using the Real Time Digital Simulator (RTDS) with a few assumptions. Simulation results of various operating conditions confirm the theoretical analysis results.
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.
Polycrystalline silicon availability for photovoltaic and semiconductor industries
NASA Technical Reports Server (NTRS)
Ferber, R. R.; Costogue, E. N.; Pellin, R.
1982-01-01
Markets, applications, and production techniques for Siemens process-produced polycrystalline silicon are surveyed. It is noted that as of 1982 a total of six Si materials suppliers were servicing a worldwide total of over 1000 manufacturers of Si-based devices. Besides solar cells, the Si wafers are employed for thyristors, rectifiers, bipolar power transistors, and discrete components for control systems. An estimated 3890 metric tons of semiconductor-grade polycrystalline Si will be used in 1982, and 6200 metric tons by 1985. Although the amount is expected to nearly triple between 1982-89, research is being carried out on the formation of thin films and ribbons for solar cells, thereby eliminating the waste produced in slicing Czolchralski-grown crystals. The free-world Si production in 1982 is estimated to be 3050 metric tons. Various new technologies for the formation of polycrystalline Si at lower costs and with less waste are considered. New entries into the industrial Si formation field are projected to produce a 2000 metric ton excess by 1988.
MCTs and IGBTs - A comparison of performance in power electronic circuits
NASA Technical Reports Server (NTRS)
Sul, S. K.; Profumo, F.; Cho, G. H.; Lipo, T. A.
1989-01-01
There is a continuous demand for improvements in the quality of switching power devices, such as higher switching frequency, higher withstand voltage capability, larger current-handling capability, and lower conduction losses. However, for single-conduction-mechanism devices (SCRs, GTOs, BJTs, FETs), possessing all these features is probably unrealizable for physical reasons. An attractive solution appears to be double-mechanism devices, in which the features of both a minority carrier device (BJT or SCR) and a majority carrier device (MOSFET) are embedded. Both IGBTs (insulated-gate bipolar transistors) and MCTs (MOS-controlled thyristors) belong to this family of double-mechanism devices and promise to have a major impact on converter circuit signs. The authors deal with the major features of these two devices, pointing out those that are most critical to the design of converter topologies. In particular, the two devices have been tested both in a chopper and in two resonant link converter topologies, and the experimental results are reported.
Kumar Sahu, Rabindra; Panda, Sidhartha; Biswal, Ashutosh; Chandra Sekhar, G T
2016-03-01
In this paper, a novel Tilt Integral Derivative controller with Filter (TIDF) is proposed for Load Frequency Control (LFC) of multi-area power systems. Initially, a two-area power system is considered and the parameters of the TIDF controller are optimized using Differential Evolution (DE) algorithm employing an Integral of Time multiplied Absolute Error (ITAE) criterion. The superiority of the proposed approach is demonstrated by comparing the results with some recently published heuristic approaches such as Firefly Algorithm (FA), Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) optimized PID controllers for the same interconnected power system. Investigations reveal that proposed TIDF controllers provide better dynamic response compared to PID controller in terms of minimum undershoots and settling times of frequency as well as tie-line power deviations following a disturbance. The proposed approach is also extended to two widely used three area test systems considering nonlinearities such as Generation Rate Constraint (GRC) and Governor Dead Band (GDB). To improve the performance of the system, a Thyristor Controlled Series Compensator (TCSC) is also considered and the performance of TIDF controller in presence of TCSC is investigated. It is observed that system performance improves with the inclusion of TCSC. Finally, sensitivity analysis is carried out to test the robustness of the proposed controller by varying the system parameters, operating condition and load pattern. It is observed that the proposed controllers are robust and perform satisfactorily with variations in operating condition, system parameters and load pattern. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.
FACTS Devices Cost Recovery During Congestion Management in Deregulated Electricity Markets
NASA Astrophysics Data System (ADS)
Sharma, Ashwani Kumar; Mittapalli, Ram Kumar; Pal, Yash
2016-09-01
In future electricity markets, flexible alternating current transmission system (FACTS) devices will play key role for providing ancillary services. Since huge cost is involved for the FACTS devices placement in the power system, the cost invested has to be recovered in their life time for the replacement of these devices. The FACTS devices in future electricity markets can act as an ancillary services provider and have to be remunerated. The main contributions of the paper are: (1) investment recovery of FACTS devices during congestion management such as static VAR compensator and unified power flow controller along with thyristor controlled series compensator using non-linear bid curves, (2) the impact of ZIP load model on the FACTS cost recovery of the devices, (3) the comparison of results obtained without ZIP load model for both pool and hybrid market model, (4) secure bilateral transactions incorporation in hybrid market model. An optimal power flow based approach has been developed for maximizing social welfare including FACTS devices cost. The optimal placement of the FACTS devices have been obtained based on maximum social welfare. The results have been obtained for both pool and hybrid electricity market for IEEE 24-bus RTS.
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.
Power flow control using quadrature boosters
NASA Astrophysics Data System (ADS)
Sadanandan, Sandeep N.
A power system that can be controlled within security constraints would be an advantage to power planners and real-time operators. Controlling flows can lessen reliability issues such as thermal limit violations, power stability problems, and/or voltage stability conditions. Control of flows can also mitigate market issues by reducing congestion on some lines and rerouting power to less loaded lines or onto preferable paths. In the traditional control of power flows, phase shifters are often used. More advanced methods include using Flexible AC Transmission System (FACTS) Controllers. Some examples include Thyristor Controlled Series Capacitors, Synchronous Series Static Compensators, and Unified Power Flow Controllers. Quadrature Boosters (QBs) have similar structures to phase-shifters, but allow for higher voltage magnitude during real power flow control. In comparison with other FACTS controllers QBs are not as complex and not as expensive. The present study proposes to use QBs to control power flows on a power system. With the inclusion of QBs, real power flows can be controlled to desired scheduled values. In this thesis, the linearized power flow equations used for power flow analysis were modified for the control problem. This included modifying the Jacobian matrix, the power error vector, and calculating the voltage injected by the quadrature booster for the scheduled real power flow. Two scenarios were examined using the proposed power flow control method. First, the power flow in a line in a 5-bus system was modified with a QB using the method developed in this thesis. Simulation was carried out using Matlab. Second, the method was applied to a 30-bus system and then to a 118-bus system using several QBs. In all the cases, the calculated values of the QB voltages led to desired power flows in the designated line.
Power Supply Changes for NSTX Resistive Wall Mode Coils
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ramakrishnan, S S.
The National Spherical Torus Experiment (NSTX) has been designed and installed in the existing facilities at Princeton Plasma Physics Laboratory (PPPL). Most of the hardware, plant facilities, auxiliary sub-systems, and power systems originally used for the Tokamak Fusion Test Reactor (TFTR) have been used with suitable modifications to reflect NSTX needs. Prior to 2004, the NSTX power system was feeding twelve (12) circuits in the machine. In 2004 the Resistive Wall Mode (RWM) Coils were installed on the machine to correct error fields. There are six of these coils installed around the machine in the mid-plane. Since these coils needmore » fast and accurate controls, a Switching Power Amplifier (SPA) with three sub-units was procured, installed and commissioned along with other power loop components. Two RWM Coils were connected in series and fed from one SPA sub-unit. After the initial RWM campaign, operational requirements evolved such that each of the RWM coils now requires separate power and control. Hence a second SPA with three sub-units has been procured and installed. The second unit is of improved design and has the controls and power components completely isolated. The existing thyristor rectifier is used as DC Link to both of the Switching Power Amplifiers. The controls for the RWM are integrated into the overall computer control of the DC Power systems for NSTX. This paper describes the design changes in the RWM Power system for NSTX.« less
A static induction device manufactured by silicon direct bonding
NASA Astrophysics Data System (ADS)
Chen, Xin'an; Liu, Su; Huang, Qing'an
2004-07-01
It is always a key problem how to improve the gate-source breakdown voltage (VGK) of static induction devices during manufacturing. By using a silicon direct bonding process to replace the high resistivity epitaxy process, a bonding buried gate structure is formed, which is different from an epitaxy buried gate structure. The new structure can improve the gate-source breakdown voltage from the process and the structure. It is shown that the bonding buried gate structure is a promising structure, that can improve the VGK and other performances of devices, by manufacture of a static induction thyristor.
2003-10-01
7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) U.S. Army Research Laboratory ATTN: AMSRL-SE-DP 2800 Powder Mill Road Adelphi, MD 20783-1197...ADDRESS(ES) U.S. Army Research Laboratory 2800 Powder Mill Road Adelphi, MD 20783-1197 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 12. DISTRIBUTION...limited to 250 V. The junction termination extension (JTE) reduces the electric field crowding at the edges of the VI + – S1 S2 D1 D2 S3 S4 D3 D4 S5
Inverter design for high frequency power distribution
NASA Technical Reports Server (NTRS)
King, R. J.
1985-01-01
A class of simple resonantly commutated inverters are investigated for use in a high power (100 KW - 1000 KW) high frequency (10 KHz - 20 KHz) AC power distribution system. The Mapham inverter is found to provide a unique combination of large thyristor turn-off angle and good utilization factor, much better than an alternate 'current-fed' inverter. The effects of loading the Mapham inverter entirely with rectifier loads are investigated by simulation and with an experimental 3 KW 20 KHz inverter. This inverter is found to be well suited to a power system with heavy rectifier loading.
High voltage power supply with modular series resonant inverters
Dreifuerst, Gary R.; Merritt, Bernard T.
1995-01-01
A relatively small and compact high voltage, high current power supply for a laser utilizes a plurality of modules containing series resonant half bridge inverters. A pair of reverse conducting thyristors are incorporated in each series resonant inverter module such that the series resonant inverter modules are sequentially activated in phases 360.degree./n apart, where n=number of modules for n>2. Selective activation of the modules allows precise output control reducing ripple and improving efficiency. Each series resonant half bridge inverter module includes a transformer which has a cooling manifold for actively circulating a coolant such as water, to cool the transformer core as well as selected circuit elements. Conductors connecting and forming various circuit components comprise hollow, electrically conductive tubes such as copper. Coolant circulates through the tubes to remove heat. The conductive tubes act as electrically conductive lines for connecting various components of the power supply. Where it is desired to make electrical isolation breaks, tubes comprised of insulating material such as nylon are used to provide insulation and continue the fluid circuit.
High voltage power supply with modular series resonant inverters
Dreifuerst, G.R.; Merritt, B.T.
1995-07-18
A relatively small and compact high voltage, high current power supply for a laser utilizes a plurality of modules containing series resonant half bridge inverters. A pair of reverse conducting thyristors are incorporated in each series resonant inverter module such that the series resonant inverter modules are sequentially activated in phases 360{degree}/n apart, where n=number of modules for n>2. Selective activation of the modules allows precise output control reducing ripple and improving efficiency. Each series resonant half bridge inverter module includes a transformer which has a cooling manifold for actively circulating a coolant such as water, to cool the transformer core as well as selected circuit elements. Conductors connecting and forming various circuit components comprise hollow, electrically conductive tubes such as copper. Coolant circulates through the tubes to remove heat. The conductive tubes act as electrically conductive lines for connecting various components of the power supply. Where it is desired to make electrical isolation breaks, tubes comprised of insulating material such as nylon are used to provide insulation and continue the fluid circuit. 11 figs.
Multicriteria Selection of Optimal Location of TCSC in a Competitive Energy Market
NASA Astrophysics Data System (ADS)
Alomoush, Muwaffaq I.
2010-05-01
The paper investigates selection of the best location of thyristor-controlled series compensator (TCSC) in a transmission system from many candidate locations in a competitive energy market such that the TCSC causes a net valuable impact on congestion management outcome, transmission utilization, transmission losses, voltage stability, degree of fulfillment of spot market contracts, and system security. The problem is treated as a multicriteria decision-making process such that the candidate locations of TCSC are the alternatives and the conflicting objectives are the outcomes of the dispatch process, which may have different importance weights. The paper proposes some performance indices that the dispatch decision-making entity can use to measure market dispatch outcomes of each alternative. Based on agreed-upon preferences, the measures presented may help the decision maker compare and rank dispatch scenarios to ultimately decide which location is the optimal one. To solve the multicriteria decision, we use the preference ranking organization method for enrichment evaluations (PROMETHEE), which is a multicriteria decision support method that can handle complex conflicting-objective decision-making processes.
High-voltage pulsed generator for dynamic fragmentation of rocks
NASA Astrophysics Data System (ADS)
Kovalchuk, B. M.; Kharlov, A. V.; Vizir, V. A.; Kumpyak, V. V.; Zorin, V. B.; Kiselev, V. N.
2010-10-01
A portable high-voltage (HV) pulsed generator has been designed for rock fragmentation experiments. The generator can be used also for other technological applications. The installation consists of low voltage block, HV block, coaxial transmission line, fragmentation chamber, and control system block. Low voltage block of the generator, consisting of a primary capacitor bank (300 μF) and a thyristor switch, stores pulse energy and transfers it to the HV block. The primary capacitor bank stores energy of 600 J at the maximum charging voltage of 2 kV. HV block includes HV pulsed step up transformer, HV capacitive storage, and two electrode gas switch. The following technical parameters of the generator were achieved: output voltage up to 300 kV, voltage rise time of ˜50 ns, current amplitude of ˜6 kA with the 40 Ω active load, and ˜20 kA in a rock fragmentation regime (with discharge in a rock-water mixture). Typical operation regime is a burst of 1000 pulses with a frequency of 10 Hz. The operation process can be controlled within a wide range of parameters. The entire installation (generator, transmission line, treatment chamber, and measuring probes) is designed like a continuous Faraday's cage (complete shielding) to exclude external electromagnetic perturbations.
High-voltage pulsed generator for dynamic fragmentation of rocks.
Kovalchuk, B M; Kharlov, A V; Vizir, V A; Kumpyak, V V; Zorin, V B; Kiselev, V N
2010-10-01
A portable high-voltage (HV) pulsed generator has been designed for rock fragmentation experiments. The generator can be used also for other technological applications. The installation consists of low voltage block, HV block, coaxial transmission line, fragmentation chamber, and control system block. Low voltage block of the generator, consisting of a primary capacitor bank (300 μF) and a thyristor switch, stores pulse energy and transfers it to the HV block. The primary capacitor bank stores energy of 600 J at the maximum charging voltage of 2 kV. HV block includes HV pulsed step up transformer, HV capacitive storage, and two electrode gas switch. The following technical parameters of the generator were achieved: output voltage up to 300 kV, voltage rise time of ∼50 ns, current amplitude of ∼6 kA with the 40 Ω active load, and ∼20 kA in a rock fragmentation regime (with discharge in a rock-water mixture). Typical operation regime is a burst of 1000 pulses with a frequency of 10 Hz. The operation process can be controlled within a wide range of parameters. The entire installation (generator, transmission line, treatment chamber, and measuring probes) is designed like a continuous Faraday's cage (complete shielding) to exclude external electromagnetic perturbations.
Graded junction termination extensions for electronic devices
NASA Technical Reports Server (NTRS)
Merrett, J. Neil (Inventor); Isaacs-Smith, Tamara (Inventor); Sheridan, David C. (Inventor); Williams, John R. (Inventor)
2006-01-01
A graded junction termination extension in a silicon carbide (SiC) semiconductor device and method of its fabrication using ion implementation techniques is provided for high power devices. The properties of silicon carbide (SiC) make this wide band gap semiconductor a promising material for high power devices. This potential is demonstrated in various devices such as p-n diodes, Schottky diodes, bipolar junction transistors, thyristors, etc. These devices require adequate and affordable termination techniques to reduce leakage current and increase breakdown voltage in order to maximize power handling capabilities. The graded junction termination extension disclosed is effective, self-aligned, and simplifies the implementation process.
Graded junction termination extensions for electronic devices
NASA Technical Reports Server (NTRS)
Merrett, J. Neil (Inventor); Isaacs-Smith, Tamara (Inventor); Sheridan, David C. (Inventor); Williams, John R. (Inventor)
2007-01-01
A graded junction termination extension in a silicon carbide (SiC) semiconductor device and method of its fabrication using ion implementation techniques is provided for high power devices. The properties of silicon carbide (SiC) make this wide band gap semiconductor a promising material for high power devices. This potential is demonstrated in various devices such as p-n diodes, Schottky diodes, bipolar junction transistors, thyristors, etc. These devices require adequate and affordable termination techniques to reduce leakage current and increase breakdown voltage in order to maximize power handling capabilities. The graded junction termination extension disclosed is effective, self-aligned, and simplifies the implementation process.
NASA Astrophysics Data System (ADS)
Khan, Umer Amir; Lee, Jong-Geon; Seo, In-Jin; Amir, Faisal; Lee, Bang-Wook
2015-11-01
Voltage source converter-based HVDC systems (VSC-HVDC) are a better alternative than conventional thyristor-based HVDC systems, especially for developing multi-terminal HVDC systems (MTDC). However, one of the key obstacles in developing MTDC is the absence of an adequate protection system that can quickly detect faults, locate the faulty line and trip the HVDC circuit breakers (DCCBs) to interrupt the DC fault current. In this paper, a novel hybrid-type superconducting circuit breaker (SDCCB) is proposed and feasibility analyses of its application in MTDC are presented. The SDCCB has a superconducting fault current limiter (SFCL) located in the main current path to limit fault currents until the final trip signal is received. After the trip signal the IGBT located in the main line commutates the current into a parallel line where DC current is forced to zero by the combination of IGBTs and surge arresters. Fault simulations for three-, four- and five-terminal MTDC were performed and SDCCB performance was evaluated in these MTDC. Passive current limitation by SFCL caused a significant reduction of fault current interruption stress in the SDCCB. It was observed that the DC current could change direction in MTDC after a fault and the SDCCB was modified to break the DC current in both the forward and reverse directions. The simulation results suggest that the proposed SDCCB could successfully suppress the DC fault current, cause a timely interruption, and isolate the faulty HVDC line in MTDC.
Electronically commutated dc motors for electric vehicles
NASA Technical Reports Server (NTRS)
Maslowski, E. A.
1981-01-01
A motor development program to explore the feasibility of electronically commutated dc motors (also known as brushless) for electric cars is described. Two different design concepts and a number of design variations based on these concepts are discussed. One design concept is based on a permanent magnet, medium speed, machine rated at 7000 to 9000 rpm, and powered via a transistor inverter power conditioner. The other concept is based on a permanent magnet, high speed, machine rated at 22,000 to 26,000 rpm, and powered via a thyristor inverter power conditioner. Test results are presented for a medium speed motor and a high speed motor each of which have been fabricated using samarium cobalt permanent magnet material.
Electric converters of electromagnetic strike machine with capacitor supply
NASA Astrophysics Data System (ADS)
Usanov, K. M.; Volgin, A. V.; Kargin, V. A.; Moiseev, A. P.; Chetverikov, E. A.
2018-03-01
The application of pulse linear electromagnetic engines in small power strike machines (energy impact is 0.01...1.0 kJ), where the characteristic mode of rare beats (pulse seismic vibrator, the arch crash device bins bulk materials), is quite effective. At the same time, the technical and economic performance of such machines is largely determined by the ability of the power source to provide a large instantaneous power of the supply pulses in the winding of the linear electromagnetic motor. The use of intermediate energy storage devices in power systems of rare-shock LEME makes it possible to obtain easily large instantaneous powers, forced energy conversion, and increase the performance of the machine. A capacitor power supply of a pulsed source of seismic waves is proposed for the exploration of shallow depths. The sections of the capacitor storage (CS) are connected to the winding of the linear electromagnetic motor by thyristor dischargers, the sequence of activation of which is determined by the control device. The charge of the capacitors to the required voltage is made directly from the battery source, or through the converter from a battery source with a smaller number of batteries.
Niamul Islam, Naz; Hannan, M A; Mohamed, Azah; Shareef, Hussain
2016-01-01
Power system oscillation is a serious threat to the stability of multimachine power systems. The coordinated control of power system stabilizers (PSS) and thyristor-controlled series compensation (TCSC) damping controllers is a commonly used technique to provide the required damping over different modes of growing oscillations. However, their coordinated design is a complex multimodal optimization problem that is very hard to solve using traditional tuning techniques. In addition, several limitations of traditionally used techniques prevent the optimum design of coordinated controllers. In this paper, an alternate technique for robust damping over oscillation is presented using backtracking search algorithm (BSA). A 5-area 16-machine benchmark power system is considered to evaluate the design efficiency. The complete design process is conducted in a linear time-invariant (LTI) model of a power system. It includes the design formulation into a multi-objective function from the system eigenvalues. Later on, nonlinear time-domain simulations are used to compare the damping performances for different local and inter-area modes of power system oscillations. The performance of the BSA technique is compared against that of the popular particle swarm optimization (PSO) for coordinated design efficiency. Damping performances using different design techniques are compared in term of settling time and overshoot of oscillations. The results obtained verify that the BSA-based design improves the system stability significantly. The stability of the multimachine power system is improved by up to 74.47% and 79.93% for an inter-area mode and a local mode of oscillation, respectively. Thus, the proposed technique for coordinated design has great potential to improve power system stability and to maintain its secure operation.
Laser pumping of thyristors for fast high current rise-times
Glidden, Steven C.; Sanders, Howard D.
2013-06-11
An optically triggered semiconductor switch includes an anode metallization layer; a cathode metallization layer; a semiconductor between the anode metallization layer and the cathode metallization layer and a photon source. The semiconductor includes at least four layers of alternating doping in the form P-N-P-N, in which an outer layer adjacent to the anode metallization layer forms an anode and an outer layer adjacent the cathode metallization layer forms a cathode and in which the anode metallization layer has a window pattern of optically transparent material exposing the anode layer to light. The photon source emits light having a wavelength, with the light from the photon source being configured to match the window pattern of the anode metallization layer.
Resonant power supplies for a rapid-cycling accelerator
NASA Astrophysics Data System (ADS)
Karady, G.; Thiessen, H. A.; Schneider, E. J.
1988-10-01
A resonant power supply has been proposed as an efficient power supply for a future 60-GeV, Kaon-producing accelerator. The engineering design of the electric system of the main-ring power supplies is described. It is shown that the resonant power supply can be built with standard commercially available components. The most critical component is the bypass switch, which requires gate-turn off thyristors, connected in parallel. Standard metal-clad switchgear can be used for the AC system. The resonant power supplies can be fed directly from the 115-kV utility network, but the resonance power supplies draw pulse loads from the utility network. This pulse may produce disturbances. AC filter and reactive power compensation is needed for economical operation.
Reconfigurable ultra-thin film GDNMOS device for ESD protection in 28 nm FD-SOI technology
NASA Astrophysics Data System (ADS)
Athanasiou, Sotirios; Legrand, Charles-Alexandre; Cristoloveanu, Sorin; Galy, Philippe
2017-02-01
We propose a novel ESD protection device (GDNMOS: Gated Diode merged NMOS) fabricated with 28 nm UTBB FD-SOI high-k metal gate technology. By modifying the combination of the diode and transistor gate stacks, the robustness of the device is optimized, achieving a maximum breakdown voltage (VBR) of 4.9 V. In addition, modifications of the gate length modulate the trigger voltage (Vt1) with a minimum value of 3.5 V. Variable electrostatic doping (gate-induced) in diode and transistor body enables reconfigurable operation. A lower doping of the base enhances the bipolar gain, leading to thyristor behavior. This innovative architecture demonstrates excellent capability for high-voltage protection while maintaining a latch-up free behavior.
High Voltage Seismic Generator
NASA Astrophysics Data System (ADS)
Bogacz, Adrian; Pala, Damian; Knafel, Marcin
2015-04-01
This contribution describes the preliminary result of annual cooperation of three student research groups from AGH UST in Krakow, Poland. The aim of this cooperation was to develop and construct a high voltage seismic wave generator. Constructed device uses a high-energy electrical discharge to generate seismic wave in ground. This type of device can be applied in several different methods of seismic measurement, but because of its limited power it is mainly dedicated for engineering geophysics. The source operates on a basic physical principles. The energy is stored in capacitor bank, which is charged by two stage low to high voltage converter. Stored energy is then released in very short time through high voltage thyristor in spark gap. The whole appliance is powered from li-ion battery and controlled by ATmega microcontroller. It is possible to construct larger and more powerful device. In this contribution the structure of device with technical specifications is resented. As a part of the investigation the prototype was built and series of experiments conducted. System parameter was measured, on this basis specification of elements for the final device were chosen. First stage of the project was successful. It was possible to efficiently generate seismic waves with constructed device. Then the field test was conducted. Spark gap wasplaced in shallowborehole(0.5 m) filled with salt water. Geophones were placed on the ground in straight line. The comparison of signal registered with hammer source and sparker source was made. The results of the test measurements are presented and discussed. Analysis of the collected data shows that characteristic of generated seismic signal is very promising, thus confirms possibility of practical application of the new high voltage generator. The biggest advantage of presented device after signal characteristics is its size which is 0.5 x 0.25 x 0.2 m and weight approximately 7 kg. This features with small li-ion battery makes constructed device very mobile. The project is still developing.
Advanced electrical power system technology for the all electric aircraft
NASA Technical Reports Server (NTRS)
Finke, R. C.; Sundberg, G. R.
1983-01-01
The application of advanced electric power system technology to an all electric airplane results in an estimated reduction of the total takeoff gross weight of over 23,000 pounds for a large airplane. This will result in a 5 to 10 percent reduction in direct operating costs (DOC). Critical to this savings is the basic electrical power system component technology. These advanced electrical power components will provide a solid foundation for the materials, devices, circuits, and subsystems needed to satisfy the unique requirements of advanced all electric aircraft power systems. The program for the development of advanced electrical power component technology is described. The program is divided into five generic areas: semiconductor devices (transistors, thyristors, and diodes); conductors (materials and transmission lines); dielectrics; magnetic devices; and load management devices. Examples of progress in each of the five areas are discussed. Bipolar power transistors up to 1000 V at 100 A with a gain of 10 and a 0.5 microsec rise and fall time are presented. A class of semiconductor devices with a possibility of switching up to 100 kV is described. Solid state power controllers for load management at 120 to 1000 V and power levels to 25 kW were developed along with a 25 kW, 20 kHz transformer weighing only 3.2 kg.
A 1 MW, 100 kV, less than 100 kg space based dc-dc power converter
NASA Technical Reports Server (NTRS)
Cooper, J. R.; White, C. W.
1991-01-01
A 1 MW dc-dc power converter has been designed which has an input voltage of 5 kV +/-3 percent, an output voltage of 100 kV +/- 0.25 percent, and a run time of 1000 s at full power. The estimated system mass is 83.8 kg, giving a power density of 11.9 kW/kg. The system exceeded the weight goal of 10 kW/kg through the use of innovative components and system concepts. The system volume is approximately 0.1 cu m, and the overall system efficiency is estimated to be 87 percent. Some of the unique system features include a 50-kHz H-bridge inverter using MOS-controlled thyristors as the switching devices, a resonance transformer to step up the voltage, open-cycle cryogenic hydrogen gas cooling, and a nonrigid, inflatable housing which provides on-demand pressurization of the power converter local environment. This system scales very well to higher output powers. The weight of the 10-MW system with the same input and output voltage requirements and overall system configuration is estimated to be 575.3 kg. This gives a power density of 17.4 kW/kg, significantly higher than the 11.9 kW/kg estimated at 1 MW.
A 1 MW, 100 kV, less than 100 kg space based dc-dc power converter
NASA Astrophysics Data System (ADS)
Cooper, J. R.; White, C. W.
A 1 MW dc-dc power converter has been designed which has an input voltage of 5 kV +/-3 percent, an output voltage of 100 kV +/- 0.25 percent, and a run time of 1000 s at full power. The estimated system mass is 83.8 kg, giving a power density of 11.9 kW/kg. The system exceeded the weight goal of 10 kW/kg through the use of innovative components and system concepts. The system volume is approximately 0.1 cu m, and the overall system efficiency is estimated to be 87 percent. Some of the unique system features include a 50-kHz H-bridge inverter using MOS-controlled thyristors as the switching devices, a resonance transformer to step up the voltage, open-cycle cryogenic hydrogen gas cooling, and a nonrigid, inflatable housing which provides on-demand pressurization of the power converter local environment. This system scales very well to higher output powers. The weight of the 10-MW system with the same input and output voltage requirements and overall system configuration is estimated to be 575.3 kg. This gives a power density of 17.4 kW/kg, significantly higher than the 11.9 kW/kg estimated at 1 MW.
Optically isolated, 2 kHz repetition rate, 4 kV solid-state pulse trigger generator.
Barnett, D H; Parson, J M; Lynn, C F; Kelly, P M; Taylor, M; Calico, S; Scott, M C; Dickens, J C; Neuber, A A; Mankowski, J J
2015-03-01
This paper presents the design and operation characteristics of a solid-state high voltage pulse generator. Its primary utilization is aimed at triggering a gaseous spark gap with high repeatability. Specifically, the trigger generator is designed to achieve a risetime on the order of 0.1 kV/ns to trigger the first stage, trigatron spark gap of a 10-stage, 500 kV Marx generator. The major design components are comprised of a 60 W constant current DC-DC converter for high voltage charging, a single 4 kV thyristor, a step-up pulse transformer, and magnetic switch for pulse steepening. A risetime of <30 ns and pulse magnitude of 4 kV is achieved matching the simulated performance of the design.
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.
Voltage stability analysis in the new deregulated environment
NASA Astrophysics Data System (ADS)
Zhu, Tong
Nowadays, a significant portion of the power industry is under deregulation. Under this new circumstance, network security analysis is more critical and more difficult. One of the most important issues in network security analysis is voltage stability analysis. Due to the expected higher utilization of equipment induced by competition in a power market that covers bigger power systems, this issue is increasingly acute after deregulation. In this dissertation, some selected topics of voltage stability analysis are covered. In the first part, after a brief review of general concepts of continuation power flow (CPF), investigations on various matrix analysis techniques to improve the speed of CPF calculation for large systems are reported. Based on these improvements, a new CPF algorithm is proposed. This new method is then tested by an inter-area transaction in a large inter-connected power system. In the second part, the Arnoldi algorithm, the best method to find a few minimum singular values for a large sparse matrix, is introduced into the modal analysis for the first time. This new modal analysis is applied to the estimation of the point of voltage collapse and contingency evaluation in voltage security assessment. Simulations show that the new method is very efficient. In the third part, after transient voltage stability component models are investigated systematically, a novel system model for transient voltage stability analysis, which is a logical-algebraic-differential-difference equation (LADDE), is offered. As an example, TCSC (Thyristor controlled series capacitors) is addressed as a transient voltage stabilizing controller. After a TCSC transient voltage stability model is outlined, a new TCSC controller is proposed to enhance both fault related and load increasing related transient voltage stability. Its ability is proven by the simulation.
Design and Testing of a Small Inductive Pulsed Plasma Thruster
NASA Technical Reports Server (NTRS)
Martin, Adam K.; Eskridge, Richard H.; Dominguez, Alexandra; Polzin, Kurt A.; Riley, Daniel P.; Kimberlin, Adam C.
2015-01-01
The design and testing of a small inductive pulsed plasma thruster (IPPT), shown in Fig. 1 with all the major subsystems required for a thruster of this kind are described. Thrust measurements and imaging of the device operated in rep-rated mode are presented to quantify the performance envelope of the device. The small IPPT described in this paper was designed to serve as a test-bed for the pulsed gas-valves and solid-state switches required for a IPPTs. A modular design approach was used to permit future modifications and upgrades. The thruster consists of the following sub-systems: a) a multi-turn, spiral-wound acceleration coil (27 cm o.d., 10 cm i.d.) driven by a 10 microFarad capacitor and switched with a high-voltage thyristor, b) a fast pulsed gas-valve, and c.) a glow-discharge pre-ionizer (PI) circuit. The acceleration-coil circuit may be operated at voltages up to 4 kV (the thyristor limit is 4.5 kV). The device may be operated at rep-rates up to 30 Hz with the present gas-valve. Thrust measurements and imaging of the device operated in rep-rated mode will be presented. The pre-ionizer consists of a 0.3 microFarad capacitor charged to 4 kV and connected to two annular stainless-steel electrodes bounding the area of the coil-face. The 4 kV potential is held across them and when the gas is puffed in over the coil, the PI circuit is completed, and a plasma is formed. Even at the less than optimal base-pressure in the chamber (approximately 5 × 10(exp -4) torr), the PI held-off the applied voltage, and only discharged upon command. For a capacitor charge of 2 kV the peak coil current is 4.1 kA, and during this pulse a very bright discharge (much brighter than from the PI alone) was observed (see Fig. 2). Interestingly, for discharges at this charge voltage the PI was not required as the current rise rate, dI/dt, of the coil itself was sufficient to ionize the gas.
An SCR inverter with an integral battery charger for electric vehicles
NASA Technical Reports Server (NTRS)
Thimmeach, D.
1983-01-01
The feasibility of incorporating an onboard battery charger into the inverter previously developed under a NASA contract is successfully demonstrated. The rated output power of the resulting isolated battery charger is 3.6 kW at 220 Vac with an 86 percent efficiency and a 95 percent power factor. Also achieved are improved inverter efficiency (from 90 to 93 percent at 15 kW motor shaft power), inverter peak power capability (from 26 to 34 kW), and reduced weight and volume of the combined inverter/charger package (47 kg, 49 x 44 x 24 cm). Some major conclusions are that using the inverter commutation circuitry to perform the battery charging function is advantageous, and that the input-commutated thyristor inverter has the potential to be an excellent inverter and battery charger for use in electric vehicle applications.
Two-stage single-phase grid-connected photovoltaic system with reduced complexity
NASA Astrophysics Data System (ADS)
da Silva, Cintia S.; Motta, Filipe R.; Tofoli, Fernando L.
2011-06-01
This article presents a grid-connected photovoltaic (PV) system using the classical DC-DC buck converter, which is responsible for stepping down the resulting voltage from several series-connected panels. Besides, the structure provides high power factor operation by injecting a quasi-sinusoidal current into the grid, with near no displacement in relation to the line voltage at the point of common coupling among the PV system and the loads. A CSI employing thyristors is cascaded with the DC-DC stage so that AC voltage results. The inverter output voltage level is adjusted by using a low-frequency transformer, which also provides galvanic isolation. The proposed system is described as mathematical approach and design guidelines are presented, providing an overview of the topology. An experimental prototype is also implemented, and relevant results to validate the proposal are discussed.
5.8kV SiC PiN Diode for Switching of High-Efficiency Inductive Pulsed Plasma Thruster Circuits
NASA Technical Reports Server (NTRS)
Toftul, Alexandra; Polzin, Kurt A.; Hudgins, Jerry L.
2014-01-01
Inductive Pulsed Plasma Thruster (IPPT) pulse circuits, such as those needed to operate the Pulsed Inductive Thruster (PIT), are required to quickly switch capacitor banks operating at a period of µs while conducting current at levels on the order of at least 10 kA. [1,2] For all iterations of the PIT to date, spark gaps have been used to discharge the capacitor bank through an inductive coil. Recent availability of fast, high-power solid state switching devices makes it possible to consider the use of semiconductor switches in modern IPPTs. In addition, novel pre-ionization schemes have led to a reduction in discharge energy per pulse for electric thrusters of this type, relaxing the switching requirements for these thrusters. [3,4] Solid state switches offer the advantage of greater controllability and reliability, as well as decreased drive circuit dimensions and mass relative to spark gap switches. The use of solid state devices such as Integrated Gate Bipolar Transistors (IGBTs), Gate Turn-off Thyristors (GTOs) and Silicon-Controlled Rectifiers (SCRs) often involves the use of power diodes. These semiconductor devices may be connected antiparallel to the switch for protection from reverse current, or used to reduce power loss in a circuit by clamping off current ringing. In each case, higher circuit efficiency may be achieved by using a diode that is able to transition, or 'switch,' from the forward conducting state ('on' state) to the reverse blocking state ('off' state) in the shortest amount of time, thereby minimizing current ringing and switching losses. Silicon Carbide (SiC) PiN diodes offer significant advantages to conventional fast-switching Silicon (Si) diodes for high power and fast switching applications. A wider band gap results in a breakdown voltage 10 times that of Si, so that a SiC device may have a thinner drift region for a given blocking voltage. [5] This leads to smaller, lighter devices for high voltage applications, as well as reduced forward conduction losses, faster reverse recovery time (faster turn-off), and lower-magnitude reverse recovery current. In addition, SiC devices have lower leakage current as compared to their Si counterparts, and a high thermal conductivity, potentially allowing the former to operate at higher temperatures with a smaller, lighter heatsink (or no heatsink at all).
Advanced electrical power system technology for the all electric aircraft
NASA Technical Reports Server (NTRS)
Finke, R. C.; Sundberg, G. R.
1983-01-01
The application of advanced electric power system technology to an all electric airplane results in an estimated reduction of the total takeoff gross weight of over 23,000 pounds for a large airplane. This will result in a 5 to 10 percent reduction in direct operating costs (DOC). Critical to this savings is the basic electrical power system component technology. These advanced electrical power components will provide a solid foundation for the materials, devices, circuits, and subsystems needed to satisfy the unique requirements of advanced all electric aircraft power systems. The program for the development of advanced electrical power component technology is described. The program is divided into five generic areas: semiconductor devices (transistors, thyristors, and diodes); conductors (materials and transmission lines); dielectrics; magnetic devices; and load management devices. Examples of progress in each of the five areas are discussed. Bipolar power transistors up to 1000 V at 100 A with a gain of 10 and a 0.5 microsec rise and fall time are presented. A class of semiconductor devices with a possibility of switching up to 100 kV is described. Solid state power controllers for load management at 120 to 1000 V and power levels to 25 kW were developed along with a 25 kW, 20 kHz transformer weighing only 3.2 kg. Previously announced in STAR as N83-24764
Commissioning of the new AGS MMPS transformers
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bajon,E.; Badea, V. S.; Bannon, M.
The Brookhaven AGS Main Magnet Power Supply (MMPS) is a thyristor control supply rated at 5500 Amps. +/-9000 Volts. The peak magnet power is 50 MWatts. The power supply is fed from a motor/generator manufactured by Siemens. During rectify and invert operation the P Bank power supplies are used. During the flattops the F Bank power supplies are used. The P Bank power supplies are fed from two 23 MVA transformers and the F Bank power supplies are fed from two 5.3 MYA transformers. The fundamental frequency of the F Bank power supplies is 1440 Hz, however the fundamental frequencymore » of the P banks was 720 Hz. It was very important to reduce the ripple during rectify to improve polarized proton operations. For this reason and also because the original transformers were 45 years old we replaced these transformers with new ones and we made the fundamental frequency of both P and F banks 1440 Hz. This paper will highlight the major hurdles that were involved during the installation of the new transformers. It will present waveforms while running at different power levels up to 6MW full load. It will show the transition from the F-Bank power supplies to the P-Banks and also show the improvements in ripple made on the P-Bank power supplies.« less
High power density dc-to-dc converters for aerospace applications
NASA Technical Reports Server (NTRS)
Divan, Deepakraj M.
1990-01-01
Three dc-to-dc converter topologies aimed at high-power high-frequency applications are introduced. Major system parasitics, namely, the leakage inductance of the transformer and the device output capacitance are efficiently utilized. Of the three circuits, the single-phase and three-phase versions of the dual active bridge topology demonstrate minimal stresses, better utilization of the transformer, bidirectional, and buck-boost modes of operation. All circuits operate at a constant switching frequency, thus simplifying design of the reactive elements. The power transfer characteristics and soft-switching regions on the Vout-Iout plane are identified. Two coaxial transformers with different cross-sections were built for a rating of 50 kVA. Based on the single-phase dual active bridge topology, a 50 kW, 50 kHz converter operating at an input voltage of 200 Vdc and an output voltage of 1600 Vdc was fabricated. Characteristics of current-fed output make the dual active bridge topologies amenable to paralleling and hence extension to megawatt power levels. Projections to a 1 MW system operating from a 500 Vdc input, at an output voltage of 10 kVdc and a switching frequency of 50 kHz, using MOS-controlled thyristors, coaxially wound transformers operating at three times the present current density with cooling, and multilayer ceramic capacitors, suggests an overall power density of 0.075 to 0.08 kg/kW and an overall efficiency of 96 percent.
Power system applications of fiber optics
NASA Technical Reports Server (NTRS)
Kirkham, H.; Johnston, A.; Lutes, G.; Daud, T.; Hyland, S.
1984-01-01
Power system applications of optical systems, primarily using fiber optics, are reviewed. The first section reviews fibers as components of communication systems. The second section deals with fiber sensors for power systems, reviewing the many ways light sources and fibers can be combined to make measurements. Methods of measuring electric field gradient are discussed. Optical data processing is the subject of the third section, which begins by reviewing some widely different examples and concludes by outlining some potential applications in power systems: fault location in transformers, optical switching for light fired thyristors and fault detection based on the inherent symmetry of most power apparatus. The fourth and final section is concerned with using optical fibers to transmit power to electric equipment in a high voltage situation, potentially replacing expensive high voltage low power transformers. JPL has designed small photodiodes specifically for this purpose, and fabricated and tested several samples. This work is described.
NASA Astrophysics Data System (ADS)
Daniel, Erik Stephen
In this thesis we present the results of experimental and theoretical studies of two quantum effect devices--the Tunnel Switch Diode (TSD) and the Velocity Modulation Transistor (VMT). We show that TSD devices can be fabricated such that they behave (semi-quantitatively) as predicted by simple analytical models and more advanced drift-diffusion simulations. These devices possess characteristics, such as on-state currents which range over nearly five orders of magnitude, and on/off current ratios which are even larger, which may allow for a practical implementation of a very dense transistorless SRAM architecture and possibly other novel circuit designs. We demonstrate that many TSD properties can be explained by analogy to a thyristor. In particular, we show that the thin oxide layer in the TSD plays a critical role, and that this can be understood in terms of current injection through the oxide, analogous to transport through the "current limiting" layer in a thyristor. As this oxide layer can be subjected to extreme stress during device operation, we have studied the effect of this stress on device behavior. We demonstrate many significant stress-dependent effects, and identify structures and operation modes which minimize these effects. We propose an InAs/GaSb/AlSb VMT which may allow for larger conductance modulation and higher temperature operation than has been demonstrated in similar GaAs/AlAs structures. Fundamental differences in device operation in the two materials systems and unusual transport mechanisms in the InAs/GaSb/AlSb system are identified as a result of the band lineups in the two systems. Boltzmann transport simulations are developed and presented, allowing a qualitative description of the transport in the InAs/GaSb/AlSb structure. Band structure calculations are carried out, allowing for device design. While no working VMT devices were produced, this is believed to be due to processing and crystal growth problems. We present methods used to overcome or circumvent a number of processing problems which resulted in shorting of the gate to the source/drain contacts. The results of electrical measurements are given, which may allow for identification of further obstacles to the production of working devices.
NASA Technical Reports Server (NTRS)
Neudeck, Philip G.; Fazi, Christian
1999-01-01
This paper outlines the dynamic reverse-breakdown characteristics of low-voltage (<250 V) small-area <5 x 10(exp -4) sq cm 4H-SiC p(sup +)n diodes subjected to nonadiabatic breakdown-bias pulsewidths ranging from 0.1 to 20 microseconds. 4H-SiC diodes with and without elementary screw dislocations exhibited positive temperature coefficient of breakdown voltage and high junction failure power densities approximately five times larger than the average failure power density of reliable silicon pn rectifiers. This result indicates that highly reliable low-voltage SiC rectifiers may be attainable despite the presence of elementary screw dislocations. However, the impact of elementary screw dislocations on other more useful 4H-SiC power device structures, such as high-voltage (>1 kV) pn junction and Schottky rectifiers, and bipolar gain devices (thyristors, IGBT's, etc.) remains to be investigated.
A 490 W transversely excited atmospheric CO2 spark gap laser with added H2
NASA Astrophysics Data System (ADS)
Zand, M.; Koushki, A. M.; Neshati, R.; Kia, B.; Khorasani, K.
2018-02-01
In this paper we present a new design for a high pulse repetition rate transversely excited atmospheric CO2 laser with ultraviolet pre-ionization. A new method of fast thyristor capacitor charging and discharging by a spark gap is used. The effect of H2 gas addition on the output and stability of a transversely excited atmospheric laser operating with a basic mixture of CO2, N2 and He is investigated. The output power was increased by adding H2 to the gas mixture ratio of CO2:N2:He:H2 = 1:1:8:0.5 at total pressure of 850 mbar. An average power of 490 W at 110 Hz with 4.5 J per pulse was obtained. The laser efficiency was 11.2% and oxygen gas was used in the spark gap for electron capture to reduce the recovery time and increase the repetition rate.
Dome flat-field system for 1.3-m Araki Telescope
NASA Astrophysics Data System (ADS)
Yoshikawa, Tomohiro; Ikeda, Yuji; Fujishiro, Naofumi; Ichizawa, Shunsuke; Arai, Akira; Isogai, Mizuki; Yonehara, Atsunori; Kawakita, Hideyo
2012-09-01
We report the system/optics design and performance of the dome flat-field system for the Araki Telescope, a 1.3- m optical/near-infrared telescope at Koyama Astronomical Observatory in Japan. A variety of instruments are attached to the telescope. The optical imager, which is intended to search for exoplanets, requires an illumination flatness within 1% on the focal plane over the 17-arcmin FOV. Illumination flatness at both the pupil plane and the focal plane of the telescope is essential for calibration of the transmittance of the optical system. We devised an optical design for the flat-field system that satisfies illumination flatness at both the focal and pupil planes using the non-sequential ray tracing software LightTools. We considered far-field illumination pattern of the lamps, scattering surface reflectance distribution of the screen, telescope structure, primary/secondary mirrors, and mirror baffles. We achieved a flat illumination distribution of 0.9% at the focal plane. The systems performance was tested by comparison with a cloud-flat frame, which was derived by imaging cloud cover illuminated by city lights. The calibration data for the dome flat-field system agree well with the cloud-flat frame within 1% for the g' and i' bands of the imager, but the r0 band data does not meet the requirement (less than or equal to 2). Moreover, various instruments require a focal plane illuminance ranging over three orders of magnitude. We used six high-power (60W) halogen lamps; the output power is remotely controlled by a thyristor-driven dimmer and a bypass circuit to an autotransformer.
An In-Rush Current Suppression Technique for the Solid-State Transfer Switch System
NASA Astrophysics Data System (ADS)
Cheng, Po-Tai; Chen, Yu-Hsing
More and more utility companies provide dual power feeders as a premier service of high power quality and reliability. To take advantage of this, the solid-state transfer switch (STS) is adopted to protect the sensitive load against the voltage sag. However, the fast transfer process may cause in-rush current on the load-side transformer due to the resulting DC-offset in its magnetic flux as the load-transfer is completed. The in-rush current can reach 2∼6 p.u. and it may trigger the over-current protections on the power feeder. This paper develops a flux estimation scheme and a thyristor gating scheme based on the impulse commutation bridge STS (ICBSTS) to minimize the DC-offset on the magnetic flux. By sensing the line voltages of both feeders, the flux estimator can predict the peak transient flux linkage at the moment of load-transfer and evaluate a suitable moment for the transfer to minimize the in-rush current. Laboratory test results are presented to validate the performance of the proposed system.
NASA Astrophysics Data System (ADS)
Nanato, N.; Kobayashi, Y.
AC high temperature superconducting (HTS) coils have been developed for transformers, motors and so on. Quench detection and protection system are essential for safety operations of the AC HTS facilities. The balance voltage method is universally used for the quench detection and protection, however especially for AC operations, the method has risks in terms of high voltage sparks. Because the method needs a voltage tap soldered to a midpoint of the coil winding and the AC HTS facilities generally operate at high voltages and therefore high voltage sparks may occur at the midpoint with no insulation. We have proposed the active power method for the quench detection and protection. The method requires no voltage tap on the midpoint of the coil winding and therefore it has in-built effectiveness for the AC HTS facilities. In this paper, we show that the method can detect the quench in an HTS transformer and moreover our proposed quench protection circuits which consist of thyristors are simple and useful for the AC HTS facilities.
Method to Eliminate Flux Linkage DC Component in Load Transformer for Static Transfer Switch
2014-01-01
Many industrial and commercial sensitive loads are subject to the voltage sags and interruptions. The static transfer switch (STS) based on the thyristors is applied to improve the power quality and reliability. However, the transfer will result in severe inrush current in the load transformer, because of the DC component in the magnetic flux generated in the transfer process. The inrush current which is always 2~30 p.u. can cause the disoperation of relay protective devices and bring potential damage to the transformer. The way to eliminate the DC component is to transfer the related phases when the residual flux linkage of the load transformer and the prospective flux linkage of the alternate source are equal. This paper analyzes how the flux linkage of each winding in the load transformer changes in the transfer process. Based on the residual flux linkage when the preferred source is completely disconnected, the method to calculate the proper time point to close each phase of the alternate source is developed. Simulation and laboratory experiments results are presented to show the effectiveness of the transfer method. PMID:25133255
Method to eliminate flux linkage DC component in load transformer for static transfer switch.
He, Yu; Mao, Chengxiong; Lu, Jiming; Wang, Dan; Tian, Bing
2014-01-01
Many industrial and commercial sensitive loads are subject to the voltage sags and interruptions. The static transfer switch (STS) based on the thyristors is applied to improve the power quality and reliability. However, the transfer will result in severe inrush current in the load transformer, because of the DC component in the magnetic flux generated in the transfer process. The inrush current which is always 2 ~ 30 p.u. can cause the disoperation of relay protective devices and bring potential damage to the transformer. The way to eliminate the DC component is to transfer the related phases when the residual flux linkage of the load transformer and the prospective flux linkage of the alternate source are equal. This paper analyzes how the flux linkage of each winding in the load transformer changes in the transfer process. Based on the residual flux linkage when the preferred source is completely disconnected, the method to calculate the proper time point to close each phase of the alternate source is developed. Simulation and laboratory experiments results are presented to show the effectiveness of the transfer method.
Design and Construction of Versatile Experiment Spherical Torus (VEST) at Seoul National University
NASA Astrophysics Data System (ADS)
An, Younghwa; Chung, Kyoung-Jae; Jung, Bongki; Lee, Hyunyeong; Sung, Choongki; Kim, Hyun-Seok; Na, Yong-Su; Hwang, Yong-Seok
2011-10-01
A new spherical torus, named as VEST (Versatile Experiment Spherical Torus), has been built at Seoul National University to investigate versatile research topics such as double null merging start-up, divertor engineering and non-inductive current drive. VEST is characterized by two partial solenoid coils installed at both vertical ends of a center stack, which will be used for double null merging start-up schemes. A poloidal field (PF) coil system including the partial solenoids for break-down and a long solenoid for the sustainment of merged plasma has been designed by solving circuit equations for the PF coils and vacuum vessel elements in consideration of required volt-second, null configuration and eddy current. To supply required currents to the PF coils and solenoids, power supplies based on double-swing circuit have been designed and fabricated with capacitor banks and thyristor switch assemblies. Also a power supply utilizing cost-effective commercial batteries has been developed for toroidal field(TF) coils. Detailed descriptions on the design of VEST and some initial test results will be presented.
NASA Technical Reports Server (NTRS)
Lipo, Thomas A.; Alan, Irfan
1991-01-01
Hard and soft switching test results conducted with one of the samples of first generation MOS-controlled thyristor (MCTs) and similar test results with several different samples of second generation MCT's are reported. A simple chopper circuit is used to investigate the basic switching characteristics of MCT under hard switching and various types of resonant circuits are used to determine soft switching characteristics of MCT under both zero voltage and zero current switching. Next, operation principles of a pulse density modulated converter (PDMC) for three phase (3F) to 3F two-step power conversion via parallel resonant high frequency (HF) AC link are reviewed. The details for the selection of power switches and other power components required for the construction of the power circuit for the second generation 3F to 3F converter system are discussed. The problems encountered in the first generation system are considered. Design and performance of the first generation 3F to 3F power converter system and field oriented induction moter drive based upon a 3 kVA, 20 kHz parallel resonant HF AC link are described. Low harmonic current at the input and output, unity power factor operation of input, and bidirectional flow capability of the system are shown via both computer and experimental results. The work completed on the construction and testing of the second generation converter and field oriented induction motor drive based upon specifications for a 10 hp squirrel cage dynamometer and a 20 kHz parallel resonant HF AC link is discussed. The induction machine is designed to deliver 10 hp or 7.46 kW when operated as an AC-dynamo with power fed back to the source through the converter. Results presented reveal that the proposed power level requires additional energy storage elements to overcome difficulties with a peak link voltage variation problem that limits reaching to the desired power level. The power level test of the second generation converter after the addition of extra energy storage elements to the HF link are described. The importance of the source voltage level to achieve a better current regulation for the source side PDMC is also briefly discussed. The power levels achieved in the motoring mode of operation show that the proposed power levels achieved in the generating mode of operation can also be easily achieved provided that no mechanical speed limitation were present to drive the induction machine at the proposed power level.
Sterilization mechanism of nitrogen gas plasma: induction of secondary structural change in protein.
Sakudo, Akikazu; Higa, Masato; Maeda, Kojiro; Shimizu, Naohiro; Imanishi, Yuichiro; Shintani, Hideharu
2013-07-01
The mechanism of action on biomolecules of N₂ gas plasma, a novel sterilization technique, remains unclear. Here, the effect of N₂ gas plasma on protein structure was investigated. BSA, which was used as the model protein, was exposed to N₂ gas plasma generated by short-time high voltage pulses from a static induction thyristor power supply. N₂ gas plasma-treated BSA at 1.5 kilo pulses per second showed evidence of degradation and modification when assessed by Coomassie brilliant blue staining and ultraviolet spectroscopy at 280 nm. Fourier transform infrared spectroscopy analysis was used to determine the protein's secondary structure. When the amide I region was analyzed in the infrared spectra according to curve fitting and Fourier self-deconvolution, N₂ gas plasma-treated BSA showed increased α-helix and decreased β-turn content. Because heating decreased α-helix and increased β-sheet content, the structural changes induced by N₂ gas plasma-treatment of BSA were not caused by high temperatures. Thus, the present results suggest that conformational changes induced by N₂ gas plasma are mediated by mechanisms distinct from heat denaturation. © 2013 The Societies and Wiley Publishing Asia Pty Ltd.
Sakudo, Akikazu; Toyokawa, Yoichi; Nakamura, Tetsuji; Yagyu, Yoshihito; Imanishi, Yuichiro
2017-01-01
Gas plasma, produced by a short high‑voltage pulse generated from a static induction thyristor power supply [1.5 kilo pulse/sec (kpps)], was demonstrated to inactivate Geobacillus stearothermophilus spores (decimal reduction time at 15 min, 2.48 min). Quantitative polymerase chain reaction and enzyme‑linked immunosorbent assays further indicated that nitrogen gas plasma treatment for 15 min decreased the level of intact genomic DNA and increased the level of 8-hydroxy-2'-deoxyguanosine, a major product of DNA oxidation. Three potential inactivation factors were generated during operation of the gas plasma instrument: Heat, longwave ultraviolet-A and oxidative stress (production of hydrogen peroxide, nitrite and nitrate). Treatment of the spores with hydrogen peroxide (3x2‑4%) effectively inactivated the bacteria, whereas heat treatment (100˚C), exposure to UV-A (75‑142 mJ/cm2) and 4.92 mM peroxynitrite (•ONOO‑), which is decomposed into nitrite and nitrate, did not. The results of the present study suggest the gas plasma treatment inactivates bacterial spores primarily by generating hydrogen peroxide, which contributes to the oxidation of the host genomic DNA.
Feasibility study of a latchup-based particle detector exploiting commercial CMOS technologies
NASA Astrophysics Data System (ADS)
Gabrielli, A.; Matteucci, G.; Civera, P.; Demarchi, D.; Villani, G.; Weber, M.
2009-12-01
The stimulated ignition of latchup effects caused by external radiation has so far proved to be a hidden hazard. Here this effect is described as a novel approach to detect particles by means of a solid-state device susceptible to latchup effects. In addition, the device can also be used as a circuit for reading sensors devices, leaving the capability of sensing to external sensors. The paper first describes the state-of-the-art of the project and its development over the latest years, then the present and future studies are proposed. An elementary cell composed of two transistors connected in a thyristor structure is shown. The study begins using traditional bipolar transistors since the latchup effect is originated as a parasitic circuit composed of such devices. Then, an equivalent circuit built up of MOS transistors is exploited, resulting an even more promising and challenging configuration than that obtained via bipolar transistors. As the MOS transistors are widely used at present in microelectronics devices and sensors, a latchup-based cell is proposed as a novel structure for future applications in particle detection, amplification of signal sensors and radiation monitoring.
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 evaluated.
A No-Arc DC Circuit Breaker Based on Zero-Current Interruption
NASA Astrophysics Data System (ADS)
Xiang, Xuewei; Chai, Jianyun; Sun, Xudong
2017-05-01
A dc system has no natural current zero-crossing point, so a dc arc is more difficult to extinguish than an ac arc. In order to effectively solve the problem of the dc arc, this paper proposes a dc circuit breaker (DCCB) capable of implementing a no-arc interruption. The proposed DCCB includes a main branch consisting of a mechanical switch, a diode and a current-limiting inductor, a semi-period resonance circuit consisting of a diode, an inductor and a capacitor, and a buffer branch consisting of a capacitor, a thyristor and a resistor. The mechanical switch is opened in a zero-current state, and the overvoltage caused by the counter electromotive force of the inductor does not exist. Meanwhile, the capacitor has a buffering effect on the voltage. The rising of the voltage of the mechanical switch is slower than the rising of the insulating strength of a contact gap of the mechanical switch, resulting in the contact gap not able to be broken down. Thus, the arc cannot be generated. The simulation results show that the proposed DCCB does not generate the arc in the interruption process, the rise rate of the short circuit current can be effectively limited, and the short circuit fault point can be rapidly isolated from the dc power supply.
NASA Astrophysics Data System (ADS)
Szymański, Zygmunt
2015-03-01
In the paper present's an analysis of suitableness an application of compact and hybrid drive system in hoisting machine. In the paper presented the review of constructional solutions of hoisting machines drive system, driving with AC and DC motor. In the paper presented conception of modern, energy sparing hoisting machine supply system, composed with compact motor, an supplied with transistor or thyristor converter supply system, and intelligent control system composed with multilevel microprocessor controller. In the paper present's also analysis of suitableness application an selected method of artificial intelligent in hoisting machine control system, automation system, and modern diagnostic system. In the paper one limited to analysis of: fuzzy logic method, genetic algorithms method, and modern neural net II and III generation. That method enables realization of complex control algorithms of hosting machine with insurance of energy sparing exploitation conditions, monitoring of exploitation parameters, and prediction diagnostic of hoisting machine technical state, minimization a number of failure states. In the paper present's a conception of control and diagnostic system of the hoisting machine based on fuzzy logic neural set control. In the chapter presented also a selected control algorithms and results of computer simulations realized for particular mathematical models of hoisting machine. Results of theoretical investigation were partly verified in laboratory and industrial experiments.
The new technological solution for the JT-60SA quench protection circuits
NASA Astrophysics Data System (ADS)
Gaio, E.; Maistrello, A.; Novello, L.; Matsukawa, M.; Perna, M.; Ferro, A.; Yamauchi, K.; Piovan, R.
2018-07-01
An advanced technology has been developed and employed for the main circuit breakers (CB) of the quench protection circuits (QPC) of the superconducting coils of JT-60SA: it consists in a Hybrid mechanical-static CB (HCB) composed of a mechanical Bypass switch (BPS) for conducting the continuous current, in parallel to a static circuit breaker (SCB) based on integrated gate commutated thyristor (IGCT) for current interruption. It was the result of a R&D program carried out since 2006 to identify innovative solutions for the interruption of high dc current, able to improve the maintainability and availability of the CB. The HCB developed for the JT-60SA QPC is the first realization of a dc circuit breaker based on this design approach for interrupting current of some tens of kA with reapplied voltage of some kV. It also represents the first application of hybrid technology with IGCT for protection of superconducting magnets in fusion experiments. The paper aims at giving a comprehensive overview of the main R&D activities devoted to the development of this new technological approach; then, the key aspects of the design, manufacturing and testing of the QPCs for JT-60SA, successfully completed in Naka Site in summer 2015 are presented. Finally, the significance of this research is discussed and the possible future developments, in particular in view of DEMO fusion reactor, are outlined.
Coiled transmission line pulse generators
McDonald, Kenneth Fox
2010-11-09
Methods and apparatus are provided for fabricating and constructing solid dielectric "Coiled Transmission Line" pulse generators in radial or axial coiled geometries. The pour and cure fabrication process enables a wide variety of geometries and form factors. The volume between the conductors is filled with liquid blends of monomers, polymers, oligomers, and/or cross-linkers and dielectric powders; and then cured to form high field strength and high dielectric constant solid dielectric transmission lines that intrinsically produce ideal rectangular high voltage pulses when charged and switched into matched impedance loads. Voltage levels may be increased by Marx and/or Blumlein principles incorporating spark gap or, preferentially, solid state switches (such as optically triggered thyristors) which produce reliable, high repetition rate operation. Moreover, these Marxed pulse generators can be DC charged and do not require additional pulse forming circuitry, pulse forming lines, transformers, or an a high voltage spark gap output switch. The apparatus accommodates a wide range of voltages, impedances, pulse durations, pulse repetition rates, and duty cycles. The resulting mobile or flight platform friendly cylindrical geometric configuration is much more compact, light-weight, and robust than conventional linear geometries, or pulse generators constructed from conventional components. Installing additional circuitry may accommodate optional pulse shape improvements. The Coiled Transmission Lines can also be connected in parallel to decrease the impedance, or in series to increase the pulse length.
NASA Astrophysics Data System (ADS)
Ruma; Lukes, P.; Aoki, N.; Spetlikova, E.; Hosseini, S. H. R.; Sakugawa, T.; Akiyama, H.
2013-03-01
A repetitive pulsed-power modulator, which employs a magnetic pulse compression circuit with a high-speed thyristor switch, was used to study the effects of the pulse repetition rate of input power on the physical and chemical properties of pulsed discharges in water. Positive high-voltage pulses of 20 kV with repetition rates of up to 1 kHz were used to generate a discharge in water using the point-to-plane electrode geometry. By varying the pulse repetition rate, two distinct modes of the discharge plasma were formed in water. The first mode was characterized by the formation of a corona-like discharge propagating through water in the form of streamer channels. The second mode was formed typically above 500 Hz, when the formation of streamer channels in water was suppressed and all plasmas occurred inside a spheroidal aggregate of very fine gas bubbles surrounding the tip of the high-voltage electrode. The production of hydrogen peroxide, degradation of organic dye Acid Orange 7 (AO7) and inactivation of bacteria Escherichia coli by the discharge in water were studied under different discharge plasma modes in dependence on the pulse repetition rate of input power. The efficiency of both chemical and biocidal processes induced by the plasma in water decreased significantly with pulse repetition rates above 500 Hz.
Electron density and plasma dynamics of a spherical theta pinch
NASA Astrophysics Data System (ADS)
Teske, C.; Liu, Y.; Blaes, S.; Jacoby, J.
2012-03-01
A spherical theta pinch for plasma stripper applications has been developed and investigated regarding the electron density and the plasma confinement during the pinching sequence. The setup consists of a 6 μH induction coil surrounding a 4000 ml spherical discharge vessel and a capacitor bank with interchangeable capacitors leading to an overall capacitance of 34 μF and 50 μF, respectively. A thyristor switch is used for driving the resonant circuit. Pulsed coil currents reached values of up to 26 kA with maximum induction of 500 mT. Typical gas pressures were 0.7 Pa up to 120 Pa with ArH2 (2.8% H2)-gas as a discharge medium. Stark broadening measurements of the Hβ emission line were carried out in order to evaluate the electron density of the discharge. In accordance with the density measurements, the transfer efficiency was estimated and a scaling law between electron density and discharge energy was established for the current setup. The densities reached values of up to 8 × 1022 m-3 for an energy of 1.6 kJ transferred into the plasma. Further, the pinching of the discharge plasma was documented and the different stages of the pinching process were analyzed. The experimental evidence suggests that concerning the recent setup of the spherical theta pinch, a linear scaling law between the transferred energy and the achievable plasma density can be applied for various applications like plasma strippers and pulsed ion sources.
Self-perceived oral health and salivary proteins in children with type 1 diabetes.
Javed, F; Sundin, U; Altamash, M; Klinge, B; Engström, P-E
2009-01-01
The aim was to validate self-perceived oral health with salivary IgG as an inflammatory parameter in children with type 1 diabetes. Unstimulated whole saliva samples were collected from 36 children with well controlled and 12 with poorly controlled type 1 diabetes and 40 non-diabetic children (Controls). Salivary flow rate, random blood glucose level, salivary protein concentration and immunoglobulin A and G levels were recorded using standard techniques. Data concerning oral health and diabetes status were collected. Self-perceived gingival bleeding (bleeding gums), bad breath and dry mouth were higher in diabetic children when compared with those in controls (P < 0.05). Gingival bleeding was frequently perceived by children with poorly controlled compared to well-controlled type 1 diabetes (P < 0.05) and controls (P < 0.001). Bad breath was common perceived by children with poorly controlled compared to well-controlled type 1 diabetes (P < 0.05) and controls (P < 0.0001). Salivary flow rate was lower in the diabetic children compared to controls (P < 0.01) with no difference between children with poorly controlled and well-controlled type 1 diabetes. Salivary IgG per mg protein concentration was higher in the diabetics when compared with the control group (P < 0.0001). IgG per mg protein levels were also higher in children with poorly controlled when compared with well-controlled type 1 diabetes (P < 0.05). There was no difference in IgA per mg protein and total protein concentrations between children with poorly controlled and well-controlled type 1 diabetes. Self-perceived gingival bleeding and salivary IgG per mg protein concentration were increased in children with type 1 diabetes compared with controls. These variables were also increased in children with poorly controlled compared with well-controlled type 1 diabetes.
Interval type-2 fuzzy PID controller for uncertain nonlinear inverted pendulum system.
El-Bardini, Mohammad; El-Nagar, Ahmad M
2014-05-01
In this paper, the interval type-2 fuzzy proportional-integral-derivative controller (IT2F-PID) is proposed for controlling an inverted pendulum on a cart system with an uncertain model. The proposed controller is designed using a new method of type-reduction that we have proposed, which is called the simplified type-reduction method. The proposed IT2F-PID controller is able to handle the effect of structure uncertainties due to the structure of the interval type-2 fuzzy logic system (IT2-FLS). The results of the proposed IT2F-PID controller using a new method of type-reduction are compared with the other proposed IT2F-PID controller using the uncertainty bound method and the type-1 fuzzy PID controller (T1F-PID). The simulation and practical results show that the performance of the proposed controller is significantly improved compared with the T1F-PID controller. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.
Knight, Kristin M; Thornburg, Loralei L; Pressman, Eva K
2012-01-01
To characterize the neonatal and maternal outcomes of type 2 diabetic patients as compared with type 1 diabetic patients and nondiabetic controls. We performed a retrospective cohort study reviewing perinatal outcomes of type 1 and type 2 diabetic patients and nondiabetic controls from July 2000 to August 2006. Analysis of variance, t testing and chi2 analysis were used to compare groups. Post hoc power analysis indicated 80% power was necessary to detect a 15% difference in composite poor neonatal outcomes. A total of 64 type 2 and 64 type 1 diabetic patients were compared with 256 controls. Type 1 diabetic patients had higher incidences of composite poor neonatal outcome and congenital anomalies than did type 2 diabetic and control patients. Both diabetic groups had similarly higher incidences of cesarean delivery, preeclampsia, preterm delivery, polyhydramnios and macrosomia than did controls. Type 2 diabetic patients have a decreased incidence of adverse neonatal outcomes when compared with that of type 1 diabetic patients. No difference was observed between the diabetic groups in the incidence of a majority of the adverse maternal outcomes examined, however both diabetic groups had overall worse outcomes that did nondiabetic controls.
Advanced Interval Type-2 Fuzzy Sliding Mode Control for Robot Manipulator.
Hwang, Ji-Hwan; Kang, Young-Chang; Park, Jong-Wook; Kim, Dong W
2017-01-01
In this paper, advanced interval type-2 fuzzy sliding mode control (AIT2FSMC) for robot manipulator is proposed. The proposed AIT2FSMC is a combination of interval type-2 fuzzy system and sliding mode control. For resembling a feedback linearization (FL) control law, interval type-2 fuzzy system is designed. For compensating the approximation error between the FL control law and interval type-2 fuzzy system, sliding mode controller is designed, respectively. The tuning algorithms are derived in the sense of Lyapunov stability theorem. Two-link rigid robot manipulator with nonlinearity is used to test and the simulation results are presented to show the effectiveness of the proposed method that can control unknown system well.
Equilibrium control of nonlinear verticum-type systems, applied to integrated pest control.
Molnár, S; Gámez, M; López, I; Cabello, T
2013-08-01
Linear verticum-type control and observation systems have been introduced for modelling certain industrial systems, consisting of subsystems, vertically connected by certain state variables. Recently the concept of verticum-type observation systems and the corresponding observability condition have been extended by the authors to the nonlinear case. In the present paper the general concept of a nonlinear verticum-type control system is introduced, and a sufficient condition for local controllability to equilibrium is obtained. In addition to a usual linearization, the basic idea is a decomposition of the control of the whole system into the control of the subsystems. Starting from the integrated pest control model of Rafikov and Limeira (2012) and Rafikov et al. (2012), a nonlinear verticum-type model has been set up an equilibrium control is obtained. Furthermore, a corresponding bioeconomical problem is solved minimizing the total cost of integrated pest control (combining chemical control with a biological one). Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.
Session Types for Access and Information Flow Control
NASA Astrophysics Data System (ADS)
Capecchi, Sara; Castellani, Ilaria; Dezani-Ciancaglini, Mariangiola; Rezk, Tamara
We consider a calculus for multiparty sessions with delegation, enriched with security levels for session participants and data. We propose a type system that guarantees both session safety and a form of access control. Moreover, this type system ensures secure information flow, including controlled forms of declassification. In particular, the type system prevents leaks that could result from an unrestricted use of the control constructs of the calculus, such as session opening, selection, branching and delegation. We illustrate the use of our type system with a number of examples, which reveal an interesting interplay between the constraints used in security type systems and those used in session types to ensure properties like communication safety and session fidelity.
Kumar, Anupam; Kumar, Vijay
2017-05-01
In this paper, a novel concept of an interval type-2 fractional order fuzzy PID (IT2FO-FPID) controller, which requires fractional order integrator and fractional order differentiator, is proposed. The incorporation of Takagi-Sugeno-Kang (TSK) type interval type-2 fuzzy logic controller (IT2FLC) with fractional controller of PID-type is investigated for time response measure due to both unit step response and unit load disturbance. The resulting IT2FO-FPID controller is examined on different delayed linear and nonlinear benchmark plants followed by robustness analysis. In order to design this controller, fractional order integrator-differentiator operators are considered as design variables including input-output scaling factors. A new hybridized algorithm named as artificial bee colony-genetic algorithm (ABC-GA) is used to optimize the parameters of the controller while minimizing weighted sum of integral of time absolute error (ITAE) and integral of square of control output (ISCO). To assess the comparative performance of the IT2FO-FPID, authors compared it against existing controllers, i.e., interval type-2 fuzzy PID (IT2-FPID), type-1 fractional order fuzzy PID (T1FO-FPID), type-1 fuzzy PID (T1-FPID), and conventional PID controllers. Furthermore, to show the effectiveness of the proposed controller, the perturbed processes along with the larger dead time are tested. Moreover, the proposed controllers are also implemented on multi input multi output (MIMO), coupled, and highly complex nonlinear two-link robot manipulator system in presence of un-modeled dynamics. Finally, the simulation results explicitly indicate that the performance of the proposed IT2FO-FPID controller is superior to its conventional counterparts in most of the cases. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.
Active parallel redundancy for electronic integrator-type control circuits
NASA Technical Reports Server (NTRS)
Peterson, R. A.
1971-01-01
Circuit extends concept of redundant feedback control from type-0 to type-1 control systems. Inactive channels are slaves to the active channel, if latter fails, it is rejected and slave channel is activated. High reliability and elimination of single-component catastrophic failure are important in closed-loop control systems.
Smets, Karolien; Moors, Pieter; Reynvoet, Bert
2016-01-01
Performance in a non-symbolic comparison task in which participants are asked to indicate the larger numerosity of two dot arrays, is assumed to be supported by the Approximate Number System (ANS). This system allows participants to judge numerosity independently from other visual cues. Supporting this idea, previous studies indicated that numerosity can be processed when visual cues are controlled for. Consequently, distinct types of visual cue control are assumed to be interchangeable. However, a previous study showed that the type of visual cue control affected performance using a simultaneous presentation of the stimuli in numerosity comparison. In the current study, we explored whether the influence of the type of visual cue control on performance disappeared when sequentially presenting each stimulus in numerosity comparison. While the influence of the applied type of visual cue control was significantly more evident in the simultaneous condition, sequentially presenting the stimuli did not completely exclude the influence of distinct types of visual cue control. Altogether, these results indicate that the implicit assumption that it is possible to compare performances across studies with a differential visual cue control is unwarranted and that the influence of the type of visual cue control partly depends on the presentation format of the stimuli. PMID:26869967
Pornprasert, Sakorn; Tookjai, Monthathip; Punyamung, Manoo; Pongpunyayuen, Panida; Jaiping, Kanokwan
2016-01-01
To date, the hemoglobin (Hb) typing control materials for laboratory investigation of thalassemia with low (1.8%-3.2%) and high (4%-6%) levels of HbA2 are available but there are no Hb typing quality control materials for analysis of thalassemia and hemoglobinopathies which are highly prevalent in South-East Asian countries. The main aim of the present study was to develop the lyophilized Hb typing control materials for laboratory investigation of thalassemia and hemoglobinopathies that are commonly found in South-East Asia. Erythrocytes of blood samples containing Hb Bart's, HbH, HbE, HbF, Hb Constant Spring (CS), Hb Hope, and Hb Q-Thailand were washed and dialysed with 0.85% saline solution. The erythrocytes were then lysed in 5% sucrose solution. The lyophilized Hb typing control materials were prepared by using a freeze drying (lyophilization) method. The high performance liquid chromatography (HPLC) analysis of lyophilized Hb was performed after the storage at -20 °C for 1 year and also after reconstitution and storage at 4 or -20 °C for 30 days. In addition, the Hb analysis was compared between the three different methods of HPLC, low pressure liquid chromatography (LPLC) and capillary electrophoresis (CE). Following a year of storage at -20 °C, the HPLC chromatograms of lyophilized Hb typing control materials showed similar patterns to the equivalent fresh whole blood. The stability of reconstituted Hb typing control materials was also observed through 30 days after reconstitution and storage at -20 °C. Moreover, the Hb typing control materials could be analyzed by three methods, HPLC, LPLC and CE. Even a degraded peak of HbCS was found on CE electropherogram. The lyophilized Hb typing control materials could be developed and used as control materials for investigation of thalassemia and hemoglobinopathies.
Picazo, Alejandra; Jiménez-Osorio, Angélica S; Zúñiga-Mejía, Porfirio; Pedraza-Chaverri, José; Monroy, Adriana; Rodríguez-Arellano, M Eunice; Barrera-Oviedo, Diana
2017-04-05
The antioxidant system results essential to control and prevent lipid peroxidation due to stress damage in type 2 diabetes. An example is aldehyde dehydrogenase (ALDH), an enzyme that is involved in the detoxification of aldehydes formed during lipid peroxidation. This study was conducted to evaluate ALDH activity and to determine their association with hypoglycemic treatment in type 2 diabetes patients. The study population consisted of 422 Mexican subjects: a control group and type 2 diabetes patients. Type 2 diabetes patients were re-classified as those with or without hypoglycemic treatment and those with or without glycemic control (according to glycated hemoglobin (HbA1c)). Clinical parameters, antioxidant enzyme activities (ALDH, superoxide dismutase (SOD), catalase and glutathione peroxidase) and oxidative markers (reactive oxygen species and thiobarbituric acid reactive substances (TBARS)) were evaluated. The activity of antioxidant enzymes and oxidative stress markers were higher in type 2 diabetes patients with hypoglycemic treatment and without glycemic control than control group. The activity of ALDH and SOD remained high in type 2 diabetes patients with moderate glycemic control while only ALDH's remained high in type 2 diabetes patients with tight glycemic control. Increased ALDH and SOD activities were associated with hypoglycemic therapy. TBARS levels were associated with glycemic control. The persistence of high ALDH and SOD activities in type 2 diabetes patients with glycemic control may be to avoid a significant damage due to the increase in reactive oxygen species and TBARS. It is possible that this new oxidative status prevented the development the classical complications of diabetes. Copyright © 2017 Elsevier B.V. All rights reserved.
Design Considerations for Siting Grade Control Structures
2001-12-01
require consideration before siting grade control structures. In the widest sense, the term grade control can be applied to any alteration in the...control structures. There are two basic types of grade control structures. One type can be referred to as a bed control structure as it is designed to...provide a hard point in the streambed that is capable of resisting the erosive forces of the degradational zone. The second type can be referred to
Transient stability enhancement of wind farms using power electronics and facts controllers
NASA Astrophysics Data System (ADS)
Mohammadpour, Hossein Ali
Nowadays, it is well-understood that the burning of fossil fuels in electric power station has a significant influence on the global climate due to greenhouse gases. In many countries, the use of cost-effective and reliable low-carbon electricity energy sources is becoming an important energy policy. Among different kinds of clean energy resources- such as solar power, hydro-power, ocean wave power and so on, wind power is the fastest-growing form of renewable energy at the present time. Moreover, adjustable speed generator wind turbines (ASGWT) has key advantages over the fixed-speed generator wind turbines (FSGWT) in terms of less mechanical stress, improved power quality, high system efficiency, and reduced acoustic noise. One important class of ASGWT is the doubly-fed induction generator (DFIG), which has gained a significant attention of the electric power industry due to their advantages over the other class of ASGWT, i.e. fully rated converter-based wind turbines. Because of increased integration of DFIG-based wind farms into electric power grids, it is necessary to transmit the generated power from wind farms to the existing grids via transmission networks without congestion. Series capacitive compensation of DFIG-based wind farm is an economical way to increase the power transfer capability of the transmission line connecting wind farm to the grid. For example, a study performed by ABB reveals that increasing the power transfer capability of an existing transmission line from 1300 MW to 2000 MW using series compensation is 90% less than the cost of building a new transmission line. However, a factor hindering the extensive use of series capacitive compensation is the potential risk of sub- synchronous resonance (SSR). The SSR is a condition where the wind farm exchanges energy with the electric network, to which it is connected, at one or more natural frequencies of the electric or mechanical part of the combined system, comprising the wind farm and the network, and the frequency of the exchanged energy is below the fundamental frequency of the system. This phenomenon may cause severe damage in the wind farm, if not prevented. Therefore, this dissertation deals with the SSR phenomena in a capacitive series compensated wind farm. A DFIG-based wind farm, which is connected to a series compensated transmission line, is considered as a case study. The small-signal stability analysis of the system is presented, and the eigenvalues of the system are obtained. Using both modal analysis and time-domain simulation, it is shown that the system is potentially unstable due to the SSR mode. Then, three different possibilities for the addition of SSR damping controller (SSRDC) are investigated. The SSRDC can be added to (1) gate-controlled series capacitor (GCSC), (2) thyristor-controlled series capacitor (TCSC), or (3) DFIG rotor-side converter (RSC) and grid-side converter (GSC) controllers. The first and second cases are related to the series flexible AC transmission systems (FACTS) family, and the third case uses the DFIG back-to-back converters to damp the SSR. The SSRDC is designed using residue-based analysis and root locus diagrams. Using residue-based analysis, the optimal input control signal (ICS) to the SSRDC is identified that can damp the SSR mode without destabilizing other modes, and using root-locus analysis, the required gain for the SSRDC is determined. Moreover, two methods are discussed in order to estimate the optimum input signal to the SSRDC, without measuring it directly. In this dissertation, MATLAB/Simulink is used as a tool for modeling and design of the SSRDC, and PSCAD/EMTDC is used to perform time-domain simulation in order to verify the design process.
Helicopter pilots' views of air traffic controller responsibilities: a mismatch.
Martin, Daniel; Nixon, Jim
2018-02-21
Controllers and pilots must work together to ensure safe and efficient helicopter flight within the London control zone. Subjective ratings of pilot perception of controller responsibility for five key flight tasks were obtained from thirty helicopter pilots. Three types of airspace were investigated. Results indicate that there is variation in pilot understanding of controller responsibility compared to the formal regulations that define controller responsibility. Significant differences in the perception of controller responsibility were found for the task of aircraft separation in class D airspace and along helicopter routes. Analysis of the patterns of response suggests that task type rather than the airspace type may be the key factor. Results are framed using the concept of a shared mental model. This research demonstrates that pilots flying in complex London airspace have an expectation of controller responsibility for certain flight tasks, in certain airspace types that is not supported by aviation regulation. Practitioner Summary: The responsibility for tasks during flight varies according to the flight rules used and airspace type. Helicopter pilots may attribute responsibility to controllers for tasks when controllers have no responsibility as defined by regulation. This variation between pilot perceptions of controller responsibility could affect safety within the London control zone.
Rauter, Georg; Sigrist, Roland; Riener, Robert; Wolf, Peter
2015-01-01
In literature, the effectiveness of haptics for motor learning is controversially discussed. Haptics is believed to be effective for motor learning in general; however, different types of haptic control enhance different movement aspects. Thus, in dependence on the movement aspects of interest, one type of haptic control may be effective whereas another one is not. Therefore, in the current work, it was investigated if and how different types of haptic controllers affect learning of spatial and temporal movement aspects. In particular, haptic controllers that enforce active participation of the participants were expected to improve spatial aspects. Only haptic controllers that provide feedback about the task's velocity profile were expected to improve temporal aspects. In a study on learning a complex trunk-arm rowing task, the effect of training with four different types of haptic control was investigated: position control, path control, adaptive path control, and reactive path control. A fifth group (control) trained with visual concurrent augmented feedback. As hypothesized, the position controller was most effective for learning of temporal movement aspects, while the path controller was most effective in teaching spatial movement aspects of the rowing task. Visual feedback was also effective for learning temporal and spatial movement aspects.
Hoffmann, Errol R; Chan, Alan H S
2017-08-01
Much research on stereotype strength relating display and control movements for displays moving in the vertical or horizontal directions has been reported. Here we report effects of display movement angle, where the display moves at angles (relative to the vertical) of between 0° and 180°. The experiment used six different controls, four display locations relative to the operator and three types of indicator. Indicator types were included because of the strong effects of the 'scale-side principle' that are variable with display angle. A directional indicator had higher stereotype strength than a neutral indicator, and showed an apparent reversal in control/display stereotype direction beyond an angle of 90°. However, with a neutral indicator this control reversal was not present. Practitioner Summary: The effects of display moving at angles other than the four cardinal directions, types of control, location of display and types of indicator are investigated. Indicator types (directional and neutral) have an effect on stereotype strength and may cause an apparent control reversal with change of display movement angle.
The Influence of Various Types of Control on Psychophysiological Stress Reactions.
ERIC Educational Resources Information Center
Cornelius, Randolph R.; Averill, James R.
1980-01-01
The influence of personal control on reactions to shock differed as a function of the type of control and of the combination of control conditions. Behavioral control in the presence of information (cognitive control) reduced stress, whereas behavioral control in the absence of information augmented stress. (Author)
Ismail, I S; Nazaimoon, W M; Mohamad, W B; Letchuman, R; Singaraveloo, M; Pendek, R; Faridah, I; Rasat, R; Sheriff, I H; Khalid, B A
2000-01-01
Recent studies have shown that good glycaemic control can prevent the development of diabetic complications in type 1 and type 2 diabetes. We wished to observe the glycaemic control in patients from different centres in Peninsular Malaysia and the factors that determine it. We recruited 926 patients with diabetes diagnosed before age 40 years from seven different centres, with proportionate representation from the three main ethnic groups. Clinical history and physical examination were done and blood taken for HbA1c and fasting glucose. The overall glycaemic control was poor with geometric mean HbA1c of 8.6% whilst 61.1% of the patients had HbA1c greater than 8%. Glycaemic control in patients with type 2 diabetes varied between various centres and ethnic groups, with the best control obtained in Chinese patients. Significant predictors of HbA1c in both type 1 and type 2 diabetes include access to nurse educators, ethnic background and WHR. In type 2 diabetes, use of insulin was a significant predictor, while in type 1 diabetes, household income was a significant predictor. Socioeconomic status did not have a significant effect in type 2 diabetes. There were no significant differences in the glycaemic control in patients with different educational status. In conclusion, glycaemic control in big hospitals in Malaysia was poor, and was closely related to the availability of diabetes care facilities and ethnic group, rather than socioeconomic status.
Gluschenko, N; Vasylyshyn, Kh; Roschupkin, A; Lekishvili, S; Gladchenko, O
2016-01-01
The aim of this paper is to investigate the content of chromium, cobalt and nickel in serum and erythrocytes in children with type 1 diabetes mellitus, depending on the level of glycemic control. The study was conducted on 68 children with type 1 diabetes mellitus. The patients were divided into four groups based on glycemic control. Group I was composed of 9 children with optimal level of glycemic control. Group II - 25 children with suboptimal level of glycemic control. Group III - 34 children with a high risk to life level of glycemic control. Group IV (control group) consisted of 30 healthy children. Compensation state of type 1 diabetes was evaluated according to ISPAD (Consensus for the Management of Type 1 Diabetes Mellitus in Children and Adolescens 2000). The content of trace elements in biological agents was determined by atomic absorbtion spectrophotometry method with C-115M1 mass-spectrophotometer, manufactured by «Selmi» enterprise (Ukraine). It is found that there is a decrease in serum concentrations of chromium and erythrocyte content of cobalt in patients with optimal level of glycemic control. The deficiency of chromium is accompanied by the deficiency of cobalt in patients with suboptimal level of glycemic control. The lower levels of cobalt and nickel are recorded simultaneously, but there is theexcess of chromium in the erythrocytes of these patients. Patients, who suffer from 1 type diabetes mellitus and high risk for life level of glycemic control have considerable polideficiency of cobalt, nickel and chromium in serum.The increasing level of chromium was recorded only in the erythrocytes. The level of glycemic control and the duration of 1 type diabetes mellitus are important in the forecasting of the development of chronic diabetic complications. It is found that the duration of 1 type diabetes mellitus influences the levels of cobalt and nickel in serum mostly, while the level of glycemic control influences the chromium content.
Nonverbal Responses to a Threat to Interpersonal Control and the Type A Behavior Pattern.
ERIC Educational Resources Information Center
Strube, Michael J.; Werner, Carol
Research has documented two behavior patterns known as Type A and Type B. Type A behavior is characterized by competitive striving, a sense of urgency, and hostility, while Type B behavior is less aggressive and more relaxed. It has been theorized that individuals exhibiting Type A behavior have a strong need to maintain control over their…
Browne, J L; Nefs, G; Pouwer, F; Speight, J
2015-01-01
Young adults with Type 2 diabetes have higher physical morbidity and mortality than other diabetes sub-groups, but differences in psychosocial outcomes have not yet been investigated. We sought to compare depression and anxiety symptoms and self-care behaviours of young adults with Type 2 diabetes with two matched control groups. Using cross-sectional survey data from the Australian and Dutch Diabetes Management and Impact for Long-term Empowerment and Success (MILES) studies, we matched 93 young adults (aged 18-39 years) with Type 2 diabetes (case group) with: (i) 93 older adults ( ≥ 40 years) with Type 2 diabetes (Type 2 diabetes control group; matched on country, gender, education, diabetes duration and insulin use) and (ii) 93 young adults with Type 1 diabetes (Type 1 diabetes control group; matched on country, gender, age and education). Groups were compared with regard to depression symptoms (nine-item Patient Health Questionnaire), anxiety symptoms (seven-item Generalised Anxiety Disorder questionnaire) and frequency of selected self-care behaviours (single item per behaviour). Participants in the case group had higher depression scores (Cohen's d = 0.40) and were more likely to have clinically meaningful depressive symptoms (Cramer's V = 0.23) than those in the Type 2 diabetes control group. Participants in the case group had statistically equivalent depression scores to the Type 1 diabetes control group. The groups did not differ in anxiety scores. Those in the case group were less likely than both control groups to take insulin as recommended (Cramer's V = 0.24-0.34), but there were no significant differences between the groups in oral medication-taking. The case group were less likely than the Type 2 diabetes control group to eat healthily (Cramer's V = 0.16), and less likely than the Type 1 diabetes control group to be physically active (Cramer's V = 0.15). Our results suggest that Type 2 diabetes is as challenging as Type 1 diabetes for young adults and more so than for older adults. Young adults with Type 2 diabetes may require more intensive psychological and self-care support than their older counterparts. © 2014 The Authors. Diabetic Medicine © 2014 Diabetes UK.
High-performance multilayer WSe 2 field-effect transistors with carrier type control
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pudasaini, Pushpa Raj; Oyedele, Akinola; Zhang, Cheng
In this paper, high-performance multilayer WSe 2 field-effect transistor (FET) devices with carrier type control are demonstrated via thickness modulation and a remote oxygen plasma surface treatment. Carrier type control in multilayer WSe 2 FET devices with Cr/Au contacts is initially demonstrated by modulating the WSe 2 thickness. The carrier type evolves with increasing WSe 2 channel thickness, being p-type, ambipolar, and n-type at thicknesses <3, ~4, and >5 nm, respectively. The thickness-dependent carrier type is attributed to changes in the bandgap of WSe 2 as a function of the thickness and the carrier band offsets relative to the metalmore » contacts. Furthermore, we present a strong hole carrier doping effect via remote oxygen plasma treatment. It non-degenerately converts n-type characteristics into p-type and enhances field-effect hole mobility by three orders of magnitude. Finally, this work demonstrates progress towards the realization of high-performance multilayer WSe 2 FETs with carrier type control, potentially extendable to other transition metal dichalcogenides, for future electronic and optoelectronic applications.« less
High-performance multilayer WSe 2 field-effect transistors with carrier type control
Pudasaini, Pushpa Raj; Oyedele, Akinola; Zhang, Cheng; ...
2017-07-06
In this paper, high-performance multilayer WSe 2 field-effect transistor (FET) devices with carrier type control are demonstrated via thickness modulation and a remote oxygen plasma surface treatment. Carrier type control in multilayer WSe 2 FET devices with Cr/Au contacts is initially demonstrated by modulating the WSe 2 thickness. The carrier type evolves with increasing WSe 2 channel thickness, being p-type, ambipolar, and n-type at thicknesses <3, ~4, and >5 nm, respectively. The thickness-dependent carrier type is attributed to changes in the bandgap of WSe 2 as a function of the thickness and the carrier band offsets relative to the metalmore » contacts. Furthermore, we present a strong hole carrier doping effect via remote oxygen plasma treatment. It non-degenerately converts n-type characteristics into p-type and enhances field-effect hole mobility by three orders of magnitude. Finally, this work demonstrates progress towards the realization of high-performance multilayer WSe 2 FETs with carrier type control, potentially extendable to other transition metal dichalcogenides, for future electronic and optoelectronic applications.« less
Development of a multipurpose hand controller for JEMRMS
NASA Technical Reports Server (NTRS)
Matsuhira, Nobuto; Iikura, Shoichi; Asakura, Makoto; Shinomiya, Yasuo
1990-01-01
A prototype multipurpose hand controller for the JEMRMS (Japanese Experiment Module Remote Manipulator System) was developed. The hand controller (H/C) is an orthogonal type, with 6 degrees of freedom (DOF) and small size. The orthogonal type H/C is very simple for coordinate transformations and can easily control any type of manipulators. In fact, the JEMRMS is planned to have two manipulators controlled by a common H/C at this stage. The H/C was able to be used as a rate control joystick and a force reflection master arm, using an experimental 6 DOF manipulator. Good maneuverability was confirmed in the verification test. The orthogonal type H/C is suitable for use as a common H/C for the two manipulators of the JEMRMS.
46 CFR 112.43-5 - Controls on island type vessels.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 4 2014-10-01 2014-10-01 false Controls on island type vessels. 112.43-5 Section 112.43-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING EMERGENCY LIGHTING AND POWER SYSTEMS Emergency Lighting Systems § 112.43-5 Controls on island type vessels. On an...
46 CFR 112.43-5 - Controls on island type vessels.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 4 2012-10-01 2012-10-01 false Controls on island type vessels. 112.43-5 Section 112.43-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING EMERGENCY LIGHTING AND POWER SYSTEMS Emergency Lighting Systems § 112.43-5 Controls on island type vessels. On an...
46 CFR 112.43-5 - Controls on island type vessels.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 4 2013-10-01 2013-10-01 false Controls on island type vessels. 112.43-5 Section 112.43-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING EMERGENCY LIGHTING AND POWER SYSTEMS Emergency Lighting Systems § 112.43-5 Controls on island type vessels. On an...
46 CFR 112.43-5 - Controls on island type vessels.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false Controls on island type vessels. 112.43-5 Section 112.43-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING EMERGENCY LIGHTING AND POWER SYSTEMS Emergency Lighting Systems § 112.43-5 Controls on island type vessels. On an...
46 CFR 112.43-5 - Controls on island type vessels.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false Controls on island type vessels. 112.43-5 Section 112.43-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING EMERGENCY LIGHTING AND POWER SYSTEMS Emergency Lighting Systems § 112.43-5 Controls on island type vessels. On an...
The urinary microbiome in women with mixed urinary incontinence compared to similarly aged controls.
Komesu, Yuko M; Richter, Holly E; Carper, Benjamin; Dinwiddie, Darrell L; Lukacz, Emily S; Siddiqui, Nazema Y; Sung, Vivian W; Zyczynski, Halina M; Ridgeway, Beri; Rogers, Rebecca G; Arya, Lily A; Mazloomdoost, Donna; Gantz, Marie G
2018-06-16
Previous studies have suggested that women with urinary incontinence have an altered urinary microbiome. We hypothesized that the microbiome in women with mixed urinary incontinence (MUI) differed from controls and tested this hypothesis using bacterial gene sequencing techniques. This multicenter study compared the urinary microbiome in women with MUI and similarly aged controls. Catheterized urine samples were obtained; v4-6 regions of the 16S rRNA gene were sequenced to identify bacteria. Bacterial predominance (> 50% of an individual's genera) was compared between MUI and controls. Bacterial sequences were categorized into "community types" using Dirichlet multinomial mixture (DMM) methods. Generalized linear mixed models predicted MUI/control status based on clinical characteristics and community type. Post-hoc analyses were performed in women < 51 and ≥ 51 years. Sample size estimates required 200 samples to detect a 20% difference in Lactobacillus predominance with P < 0.05. Of 212 samples, 97.6% were analyzed (123 MUI/84 controls, mean age 53 ± 11 years). Overall Lactobacillus predominance did not differ between MUI and controls (45/123 = 36.6% vs. 36/84 = 42.9%, P = 0.36). DMM analyses revealed six community types; communities differed by age (P = 0.001). A High-Lactobacillus (89.2% Lactobacillus) community had a greater proportion of controls (19/84 = 22.6%, MUI 11/123 = 8.9%). Overall, bacterial community types did not differ in MUI and controls. However, post-hoc analysis of women < 51 years found that bacterial community types distinguished MUI from controls (P = 0.041); Moderate-Lactobacillus (aOR 7.78, CI 1.85-32.62) and Mixed (aOR 7.10, CI 1.32-38.10) community types were associated with MUI. Community types did not differentiate MUI and controls in women ≥ 51 years (P = 0.94). Women with MUI and controls did not differ in overall Lactobacillus predominance. In younger women, urinary bacterial community types differentiated MUI from controls.
Manufacture and quality control of interconnecting wire hardnesses, Volume 1
NASA Technical Reports Server (NTRS)
1972-01-01
A standard is presented for manufacture, installation, and quality control of eight types of interconnecting wire harnesses. The processes, process controls, and inspection and test requirements reflected are based on acknowledgment of harness design requirements, acknowledgment of harness installation requirements, identification of the various parts, materials, etc., utilized in harness manufacture, and formulation of a typical manufacturing flow diagram for identification of each manufacturing and quality control process, operation, inspection, and test. The document covers interconnecting wire harnesses defined in the design standard, including type 1, enclosed in fluorocarbon elastomer convolute, tubing; type 2, enclosed in TFE convolute tubing lines with fiberglass braid; type 3, enclosed in TFE convolute tubing; and type 5, combination of types 3 and 4. Knowledge gained through experience on the Saturn 5 program coupled with recent advances in techniques, materials, and processes was incorporated.
Surgery in the treatment of type 2 diabetes mellitus.
Maleckas, A; Venclauskas, L; Wallenius, V; Lönroth, H; Fändriks, L
2015-03-01
The prevalence of diabetes is increasing worldwide, and most of the cases are type 2 diabetes mellitus. The relationship between type 2 diabetes mellitus and obesity is well established, and surgical treatment is widely used for obese patients with type 2 diabetes mellitus. The aim was to present current knowledge about the possible mechanisms responsible for glucose control after surgical procedures and to review the surgical treatment results. Medical literature was searched for the articles presenting the impact of surgical treatment on glycemic control, long-term results, and possible mechanisms of action among obese individuals with type 2 diabetes mellitus. Remission of type 2 diabetes mellitus after bariatric surgery depends on the definition of the remission used. Complete remission rate after surgery with the new criteria is lower than was considered before. Randomized controlled studies demonstrate that surgery is superior to best medical treatment for the patients with type 2 diabetes mellitus. The recurrence of type 2 diabetes mellitus after bariatric surgery is observed in up to 40% of cases with ≥ 5 years of follow-up. Despite the recurrence of type 2 diabetes mellitus in this group, better glycemic control and lower risk of macrovascular complications are present. Incretin effects on glycemic control after bariatric surgery are well described, but the role of other possible mechanisms (bile acids, microbiota, intestinal gluconeogenesis) in humans is unclear. Surgery is an effective treatment of type 2 diabetes mellitus in obese patients. The most optimal surgical procedure for the treatment of obese patients with type 2 diabetes mellitus is still to be established. More research is needed to explore the mechanisms of glycemic control after bariatric surgery. © The Finnish Surgical Society 2015.
ERIC Educational Resources Information Center
Crump, Matthew J. C.; Logan, Gordon D.
2010-01-01
Routine actions are commonly assumed to be controlled by hierarchically organized processes and representations. In the domain of typing theories, word-level information is assumed to activate the constituent keystrokes required to type each letter in a word. We tested this assumption directly using a novel single-letter probe technique. Subjects…
NASA Technical Reports Server (NTRS)
Joshi, S. M.
1985-01-01
Robustness properties are investigated for two types of controllers for large flexible space structures, which use collocated sensors and actuators. The first type is an attitude controller which uses negative definite feedback of measured attitude and rate, while the second type is a damping enhancement controller which uses only velocity (rate) feedback. It is proved that collocated attitude controllers preserve closed loop global asymptotic stability when linear actuator/sensor dynamics satisfying certain phase conditions are present, or monotonic increasing nonlinearities are present. For velocity feedback controllers, the global asymptotic stability is proved under much weaker conditions. In particular, they have 90 phase margin and can tolerate nonlinearities belonging to the (0,infinity) sector in the actuator/sensor characteristics. The results significantly enhance the viability of both types of collocated controllers, especially when the available information about the large space structure (LSS) parameters is inadequate or inaccurate.
NASA Astrophysics Data System (ADS)
Ye, Bo; Zhang, Wei; Sun, Zhen-jun; Guo, Lin; Deng, Chao; Chen, Ya-qi; Zhang, Hong-hai; Liu, Sheng
2015-12-01
In this paper, the authors propose rotating an external permanent magnet (EPM) to manipulate the synchronous rotation of a magnetic spiral-type wireless capsule endoscope (WCE), and the synchronous rotation of the WCE is converted to its translational motion in intestinal tract. In order to preliminarily verify the feasibility of this method, a handheld actuator (HA) controlled by micro controller unit, a magnetic spiral-type WCE and a bracket were fabricated, theoretical analysis and simulations about the control distance of this method were performed, and in ex-vivo tests were examined in porcine small intestine to verify the control distance and control performances of this method. It was demonstrated that this method showed good performances in controlling the translational motion of the magnetic spiral-type WCE, and this method has great potential to be used in clinical application.
Dysfunction of the neuromuscular junction in spinal muscular atrophy types 2 and 3.
Wadman, Renske I; Vrancken, Alexander F J E; van den Berg, Leonard H; van der Pol, W Ludo
2012-11-13
Spinal muscular atrophy (SMA) is pathologically characterized by degeneration of anterior horn cells. Recent observations in animal models of SMA and muscle tissue from patients with SMA suggest additional abnormalities in the development and maturation of the neuromuscular junction. We therefore evaluated neuromuscular junction function in SMA with repetitive nerve stimulation. In this case-control study, repetitive nerve stimulation was performed in 35 patients with SMA types 2, 3, and 4, 20 healthy controls, and 5 controls with motor neuron disease. Pathologic decremental responses (>10%) during 3-Hz repetitive nerve stimulation were observed in 17 of 35 patients (49%) with SMA types 2 and 3, but not in healthy controls or controls with motor neuron disease. None of the patients or controls had an abnormal incremental response of >60%. The presence of an abnormal decremental response was not specific for the type of SMA, nor was it associated with compound muscle action potential amplitude, clinical scores, or disease duration. Two of 4 patients with SMA type 3 who tried pyridostigmine reported increased stamina. These data suggest dysfunction of the neuromuscular junction in patients with SMA types 2 and 3. Therefore, drugs that facilitate neuromuscular transmission are candidate drugs for evaluation in carefully designed, placebo-controlled, clinical trials.
Academic abilities and glycaemic control in children and young people with Type 1 diabetes mellitus.
Semenkovich, K; Patel, P P; Pollock, A B; Beach, K A; Nelson, S; Masterson, J J; Hershey, T; Arbeláez, A M
2016-05-01
To determine if children and young people aged < 23 years with Type 1 diabetes differ in academic ability from age-matched control subjects without Type 1 diabetes and whether academic scores are related to glycaemic control. Using a cross-sectional study design, we administered cognitive and academic tests (Woodcock-Johnson III Spatial Relations, General Information, Letter-Word Recognition, Calculation and Spelling tests) to young people with Type 1 diabetes (n=61) and control subjects (n=26) aged 9-22 years. The groups did not differ in age or gender. Participants with Type 1 diabetes had a disease duration of 5-17.7 years. History of glycaemic control (HbA1c , diabetic ketoacidosis and severe hypoglycaemic episodes) was obtained via medical records and interviews. The participants with Type 1 diabetes had a lower mean estimated verbal intelligence (IQ) level compared with those in the control group (P=0.04). Greater exposure to hyperglycaemia over time was associated with lower spelling abilities within the group with Type 1 diabetes (P=0.048), even after controlling for age, gender, socio-economic status, blood glucose level at time of testing and verbal IQ (P=0.01). History of severe hypoglycaemia or ketoacidosis was not associated with differences in academic abilities. In children and young people, Type 1 diabetes was associated with a lower verbal IQ. Moreover, increased exposure to hyperglycaemia was associated with lower spelling performance. These results imply that hyperglycaemia can affect cognitive function and/or learning processes that may affect academic achievement. © 2015 Diabetes UK.
Advanced ADA Workshop Held in Biloxi, Mississippi on 24-27 January 1989
1989-01-27
Software Engineering (Break at 2:30j 6:30-8:00 Keesler AFB Reception Officers’ Club WEDNESDAY - 25 JANIJ1APY 9:00-12:00 Bldc 1002 Generics (Break at 10...TextIO.FileType: -- NO! procedure Wrong; -- problem is FileType is limited private Object Parameters A More Useful Example generic Control -Block : in out... control the precision used Float Type Parameters An Example generic type FloatType is digits <>; function Sqrt(X : FloatType) return FloatType
Architecture of conference control functions
NASA Astrophysics Data System (ADS)
Kausar, Nadia; Crowcroft, Jon
1999-11-01
Conference control is an integral part in many-to-many communications that is used to manage and co-ordinate multiple users in conferences. There are different types of conferences which require different types of control. Some of the features of conference control may be user invoked while others are for internal management of a conference. In recent years, ITU (International Telecommunication Union) and IETF (Internet Engineering Task Force) have standardized two main models of conferencing, each system providing a set of conference control functionalities that are not easily provided in the other one. This paper analyzes the main activities appropriate for different types of conferences and presents an architecture for conference control called GCCP (Generic Conference Control Protocol). GCCP interworks different types of conferencing and provides a set of conference control functions that can be invoked by users directly. As an example of interworking, interoperation of IETF's SIP and ITU's H.323 call control functions have been examined here. This paper shows that a careful analysis of a conferencing architecture can provide a set of control functions essential for any group communication model that can be extensible if needed.
Zeghlache, Samir; Kara, Kamel; Saigaa, Djamel
2015-11-01
In this paper, a robust controller for a Six Degrees of Freedom (6 DOF) coaxial trirotor helicopter control is proposed in presence of defects in the system. A control strategy based on the coupling of the interval type-2 fuzzy logic control and sliding mode control technique are used to design a controller. The main purpose of this work is to eliminate the chattering phenomenon and guaranteeing the stability and the robustness of the system. In order to achieve this goal, interval type-2 fuzzy logic control has been used to generate the discontinuous control signal. The simulation results have shown that the proposed control strategy can greatly alleviate the chattering effect, and perform good reference tracking in presence of defects in the system. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.
Khanesar, Mojtaba Ahmadieh; Kayacan, Erdal; Reyhanoglu, Mahmut; Kaynak, Okyay
2015-04-01
A novel type-2 fuzzy membership function (MF) in the form of an ellipse has recently been proposed in literature, the parameters of which that represent uncertainties are de-coupled from its parameters that determine the center and the support. This property has enabled the proposers to make an analytical comparison of the noise rejection capabilities of type-1 fuzzy logic systems with its type-2 counterparts. In this paper, a sliding mode control theory-based learning algorithm is proposed for an interval type-2 fuzzy logic system which benefits from elliptic type-2 fuzzy MFs. The learning is based on the feedback error learning method and not only the stability of the learning is proved but also the stability of the overall system is shown by adding an additional component to the control scheme to ensure robustness. In order to test the efficiency and efficacy of the proposed learning and the control algorithm, the trajectory tracking problem of a magnetic rigid spacecraft is studied. The simulations results show that the proposed control algorithm gives better performance results in terms of a smaller steady state error and a faster transient response as compared to conventional control algorithms.
Stefanowicz, Anna; Birkholz, Dorota; Myśliwiec, Małgorzata; Niedźwiecki, Maciej; Owczuk, Radosław; Balcerska, Anna
2012-01-01
Type 1 diabetes is a chronic, incurable childhood disease. Chronically uncontrolled diabetes is associated with eye, kidney, nerve, heart and blood vessel damage and function impairment. The aim of this study was to evaluate the impact of various social and environmental factors, with a particular emphasis on education, on the level of metabolic control in diabetes. The survey research was conducted in 102 children aged 0-18 years, diagnosed with type 1 diabetes. Based on the HbA(1c ) level, patients were divided into: group A (63 patients with fairly well and moderately controlled type 1 diabetes mellitus) and group B (39 patients with metabolically uncontrolled type 1 diabetes mellitus). The impact of various environmental and social factors on the degree of metabolic control of type 1 diabetes was analysed. No effect of typical environmental and social factors, such as: place of residence, gender, parents' education and their professional activity, on the level of metabolic control of type 1 diabetes was found. However, groups A and B significantly differed in the level of knowledge about diabetes and its treatment, in the regularity of meals, in possessing a nutrition scale and in the self-assessed preparation for taking care and custody of a child with type 1 diabetes. 1. Children with type 1 diabetes and their parents require ongoing education about the disease and its treatment. 2. The regularity of meals and the use of a nutrition scale have considerable impact on the level of metabolic control of the disease.
NASA Technical Reports Server (NTRS)
Phatak, A. V.; Kessler, K. M.
1975-01-01
The selection of the structure of optimal control type models for the human gunner in an anti aircraft artillery system is considered. Several structures within the LQG framework may be formulated. Two basic types are considered: (1) kth derivative controllers; and (2) proportional integral derivative (P-I-D) controllers. It is shown that a suitable criterion for model structure determination can be based on the ensemble statistics of the tracking error. In the case when the ensemble tracking steady state error is zero, it is suggested that a P-I-D controller formulation be used in preference to the kth derivative controller.
Meex, Ruth C R; Schrauwen-Hinderling, Vera B; Moonen-Kornips, Esther; Schaart, Gert; Mensink, Marco; Phielix, Esther; van de Weijer, Tineke; Sels, Jean-Pierre; Schrauwen, Patrick; Hesselink, Matthijs K C
2010-03-01
Mitochondrial dysfunction and fat accumulation in skeletal muscle (increased intramyocellular lipid [IMCL]) have been linked to development of type 2 diabetes. We examined whether exercise training could restore mitochondrial function and insulin sensitivity in patients with type 2 diabetes. Eighteen male type 2 diabetic and 20 healthy male control subjects of comparable body weight, BMI, age, and VO2max participated in a 12-week combined progressive training program (three times per week and 45 min per session). In vivo mitochondrial function (assessed via magnetic resonance spectroscopy), insulin sensitivity (clamp), metabolic flexibility (indirect calorimetry), and IMCL content (histochemically) were measured before and after training. Mitochondrial function was lower in type 2 diabetic compared with control subjects (P = 0.03), improved by training in control subjects (28% increase; P = 0.02), and restored to control values in type 2 diabetic subjects (48% increase; P < 0.01). Insulin sensitivity tended to improve in control subjects (delta Rd 8% increase; P = 0.08) and improved significantly in type 2 diabetic subjects (delta Rd 63% increase; P < 0.01). Suppression of insulin-stimulated endogenous glucose production improved in both groups (-64%; P < 0.01 in control subjects and -52% in diabetic subjects; P < 0.01). After training, metabolic flexibility in type 2 diabetic subjects was restored (delta respiratory exchange ratio 63% increase; P = 0.01) but was unchanged in control subjects (delta respiratory exchange ratio 7% increase; P = 0.22). Starting with comparable pretraining IMCL levels, training tended to increase IMCL content in type 2 diabetic subjects (27% increase; P = 0.10), especially in type 2 muscle fibers. Exercise training restored in vivo mitochondrial function in type 2 diabetic subjects. Insulin-mediated glucose disposal and metabolic flexibility improved in type 2 diabetic subjects in the face of near-significantly increased IMCL content. This indicates that increased capacity to store IMCL and restoration of improved mitochondrial function contribute to improved muscle insulin sensitivity.
Meex, Ruth C.R.; Schrauwen-Hinderling, Vera B.; Moonen-Kornips, Esther; Schaart, Gert; Mensink, Marco; Phielix, Esther; van de Weijer, Tineke; Sels, Jean-Pierre; Schrauwen, Patrick; Hesselink, Matthijs K.C.
2010-01-01
OBJECTIVE Mitochondrial dysfunction and fat accumulation in skeletal muscle (increased intramyocellular lipid [IMCL]) have been linked to development of type 2 diabetes. We examined whether exercise training could restore mitochondrial function and insulin sensitivity in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS Eighteen male type 2 diabetic and 20 healthy male control subjects of comparable body weight, BMI, age, and Vo2max participated in a 12-week combined progressive training program (three times per week and 45 min per session). In vivo mitochondrial function (assessed via magnetic resonance spectroscopy), insulin sensitivity (clamp), metabolic flexibility (indirect calorimetry), and IMCL content (histochemically) were measured before and after training. RESULTS Mitochondrial function was lower in type 2 diabetic compared with control subjects (P = 0.03), improved by training in control subjects (28% increase; P = 0.02), and restored to control values in type 2 diabetic subjects (48% increase; P < 0.01). Insulin sensitivity tended to improve in control subjects (delta Rd 8% increase; P = 0.08) and improved significantly in type 2 diabetic subjects (delta Rd 63% increase; P < 0.01). Suppression of insulin-stimulated endogenous glucose production improved in both groups (−64%; P < 0.01 in control subjects and −52% in diabetic subjects; P < 0.01). After training, metabolic flexibility in type 2 diabetic subjects was restored (delta respiratory exchange ratio 63% increase; P = 0.01) but was unchanged in control subjects (delta respiratory exchange ratio 7% increase; P = 0.22). Starting with comparable pretraining IMCL levels, training tended to increase IMCL content in type 2 diabetic subjects (27% increase; P = 0.10), especially in type 2 muscle fibers. CONCLUSIONS Exercise training restored in vivo mitochondrial function in type 2 diabetic subjects. Insulin-mediated glucose disposal and metabolic flexibility improved in type 2 diabetic subjects in the face of near–significantly increased IMCL content. This indicates that increased capacity to store IMCL and restoration of improved mitochondrial function contribute to improved muscle insulin sensitivity. PMID:20028948
Vitamin D and glycemic control in diabetes mellitus type 2.
Kostoglou-Athanassiou, Ifigenia; Athanassiou, Panagiotis; Gkountouvas, Anastasios; Kaldrymides, Philippos
2013-08-01
The extraskeletal effects of vitamin D have attracted considerable interest. Vitamin D deficiency appears to be related to the development of diabetes mellitus type 2 and the metabolic syndrome. Vitamin D may affect glucose homeostasis, vitamin D levels having been found to be inversely related to glycosylated hemoglobin levels in gestational diabetes mellitus. In addition, vitamin D appears to protect from the development of gestational diabetes mellitus. The aim was to study levels of 25-hydroxy vitamin D3 [25(OH)D3] and the relationship between 25(OH)D3 levels and glycemic control in patients with diabetes mellitus type 2. Glycosylated hemoglobin (HbA1c) and 25(OH)D3 levels were measured in a group of 120 diabetes mellitus type 2 patients. The same measurements were performed in a group of 120 control subjects of the same age and sex. 25(OH)D3 was measured by radioimmunoassay and glycosylated hemoglobin (HbA1c) was measured by high-performance liquid chromatography. 25(OH)D3 levels were lower in the diabetes mellitus type 2 patients than in the control group, being 19.26 ± 0.95 ng/ml and 25.49 ± 1.02 ng/ml, in the patient and control groups, respectively (p < 0.001, Student's t-test). 25(OH)D3 levels were found to be inversely associated with HbA1c levels in the diabetic patients (p = 0.008, r (2) = 0.058, linear regression). 25(OH)D3 levels were found to be inversely associated with HbA1c when the patient and control groups were analysed together (p < 0.001, r (2) = 0.086). Vitamin D levels appeared to be lower in diabetes mellitus type 2 patients than in the control group, vitamin D levels being related to glycemic control in diabetes mellitus type 2. These findings may have therapeutic implications as cautious vitamin D supplementation may improve glycemic control in diabetes mellitus type 2.
NASA Astrophysics Data System (ADS)
Rusdiana; Savira, M.; Syahputra, M.; Santoso, A.
2018-03-01
The aim of the study knowing the comparison creatinine plasma levels at uncontrolled type 2 diabetes mellitus and controlled type 2 diabetes mellitus patients at Primary Health Care in Binjai city of North Sumatera in Indonesia. This cross-sectional study was conductedon 40 type 2 Diabetes Mellitus patients who attended Primary Health Care in Binjai. Patients with age > 40 years old, (both sexes) were included in the study. We recorded different demographic parameter as age, Body Mass Index, Blood Pressure, and personal history status. And we examined the biochemicalparameters including Hba1c, Fasting Blood Sugar Levels (FBL) and creatinine serum. We separated into two groups base on HbA1c test, controlled type 2 diabetes mellitus and uncontrolled type 2 diabetes mellitus. We measured FBL by using the portable measuring instrument, and Thamrin clinical laboratory measured Hba1c, andwe measured creatinine plasmaby spectrophotometry in Biochemistry laboratory. With statistical analysis using T-test found that there was asignificant differencein creatinine plasma levels between uncontrolled type 2 diabetes mellitus with controlled type 2 diabetes mellitus (p<0.005).
Golombok, Susan; Rust, John; Zervoulis, Karyofyllis; Golding, Jean; Hines, Melissa
2012-06-01
Sex-typed behavior was assessed at age 3 using the Pre-School Activities Inventory, and at age 13 using the Multidimensional Gender Identity Scale, in 54 masculine boys, 57 masculine girls, 75 feminine boys, 65 feminine girls, 61 control boys, and 65 control girls. At age 13, girls who had been masculine at age 3 felt less similar to other girls, were less content being a girl, and had greater self-efficacy for male-typed activities than control girls, and girls who had been feminine at age 3 had greater self-efficacy for female-typed activities. Boys who had been feminine at age 3 felt less similar to other boys and had lower self-efficacy for male-typed activities than control boys at age 13, and boys who had been masculine at age 3 felt more competent in agentic roles. Thus, sex-typed behavior at age 3 predicted sex-typed behavior at age 13. It was concluded that the degree of sex-typed behavior shown by preschool children is a good indicator of their degree of sex-typed behavior following the transition to adolescence.
Franklin R. Ward; David V. Sandberg
1981-01-01
This publication presents tables on the behavior of fire and the resistance of fuels to control. The information is to be used with the publication, "Photo Series for Quantifying Forest Residues in the Ponderosa Pine Type, Ponderosa Pine and Associated Species Type, Lodgepole Pine Type" (Maxwell, Wayne G.; Ward, Franklin R. 1976. Gen. Tech. Rep. PNW-GTR-052....
Stettler, Christoph; Allemann, Sabin; Jüni, Peter; Cull, Carole A; Holman, Rury R; Egger, Matthias; Krähenbühl, Stephan; Diem, Peter
2006-07-01
Uncertainty persists concerning the effect of improved long-term glycemic control on macrovascular disease in diabetes mellitus (DM). We performed a systematic review and meta-analysis of randomized controlled trials comparing interventions to improve glycemic control with conventional treatment in type 1 and type 2 diabetes. Outcomes included the incidence rate ratios for any macrovascular event, cardiac events, stroke, and peripheral arterial disease, and the number needed to treat intensively during 10 years to prevent one macrovascular event. The analysis was based on 8 randomized comparisons including 1800 patients with type 1 DM (134 macrovascular events, 40 cardiac events, 88 peripheral vascular events, 6 cerebrovascular events, 11293 person-years of follow-up) and 6 comparisons including 4472 patients with type 2 DM (1587 macrovascular events, 1197 cardiac events, 87 peripheral vascular events, 303 cerebrovascular events, 43607 person-years). Combined incidence rate ratios for any macrovascular event were 0.38 (95% CI 0.26-0.56) in type 1 and 0.81 (0.73-0.91) in type 2 DM. In type 1 DM, effect was mainly based on reduction of cardiac and peripheral vascular events and, in type 2 DM, due to reductions in stroke and peripheral vascular events. Effects appear to be particularly important in younger patients with shorter duration of diabetes. Our data suggest that attempts to improve glycemic control reduce the incidence of macrovascular events both in type 1 and type 2 DM. In absolute terms, benefits are comparable, although effects on specific manifestations of macrovascular disease differ.
Iwakawa, Hiromi; Nakamura, Yasuyuki; Fukui, Tomiho; Fukuwatari, Tsutomu; Ugi, Satoshi; Maegawa, Hiroshi; Doi, Yukio; Shibata, Katsumi
2016-01-01
We examined the concentrations of water-soluble vitamins in blood and urinary excretion of 22 patients with type 2 diabetes mellitus (type 2DM) and 20 healthy control participants. Macronutrient and vitamin intakes of type 2DM subjects were measured using a weighed food record method. Control participants consumed a semipurified diet for eight days. Multiple linear regression models were used to determine whether significant differences existed in vitamin concentrations in blood independent of age, sex, and other confounding factors. Concentrations of vitamins B2, B6, C, niacin, and folate in blood were significantly lower in type 2DM subjects than in controls, independent of confounding factors. Renal clearances of vitamins B6, C, niacin, and folate were significantly higher in type 2DM subjects than in controls. In conclusion, concentrations of vitamins B2, B6, C, niacin, and folate in blood were significantly lower in type 2DM subjects than in controls, independent of confounding factors; based on the evidence of increased urinary clearance of these vitamins, the lower levels were likely due to impaired reabsorption processes.
Ismail, Sahar A; Abbas, Ahmad M; Habib, Dina; Morsy, Hanan; Saleh, Medhat A; Bahloul, Mustafa
2017-08-30
The existing literature is contradictory regarding effects of female genital mutilation/cutting (FGM/C) on sexual functions. The aim of this study was to explore the impact of type I and II FGM/C on sexual function of Egyptian women. We recruited 197 cut women and 197 control women from those visiting Assiut University hospitals for different reasons. We asked each woman to fill the Arabic female sexual function index (FSFI) (a self reported 19-item questionnaire assessing the main domains of female sexual function). Genital Examination was done to confirm the type of FGM. Female sexual dysfunction (FSD) was found in 83.8% of FGM/C cases in contrast to 64.5% of the control. The total FSFI score in the FGM/C group (19.82 ± 7.1) was significantly lower than in the control group (23.34 ± 8.1). Concerning the types of FGM/C, type 73.6% of cases had type I and 26.4% had type II. Type I FGM/C was performed mainly by physicians (62.1%) while type II was performed mainly by midwives (44.4%). FSD was found in 83.4% of FGM/C I cases and in 84.6% of FGM/C II cases. There was no statistically significant difference between the two types of FGM/C as regards total and individual domain scores except for the pain domain. There were significantly lower total and individual domain scores in both FGM/C types except for the desire domain compared to control. In this study, FGM/C was associated with reduced scores of FSFI on all domains scores, and among both types I and II, both were associated with sexual dysfunction.
Episodic Contributions to Sequential Control: Learning from a Typist's Touch
ERIC Educational Resources Information Center
Crump, Matthew J. C.; Logan, Gordon D.
2010-01-01
Sequential control over routine action is widely assumed to be controlled by stable, highly practiced representations. Our findings demonstrate that the processes controlling routine actions in the domain of skilled typing can be flexibly manipulated by memory processes coding recent experience with typing particular words and letters. In two…
Multiplicity Control in Structural Equation Modeling
ERIC Educational Resources Information Center
Cribbie, Robert A.
2007-01-01
Researchers conducting structural equation modeling analyses rarely, if ever, control for the inflated probability of Type I errors when evaluating the statistical significance of multiple parameters in a model. In this study, the Type I error control, power and true model rates of famsilywise and false discovery rate controlling procedures were…
Boltzmann-type control of opinion consensus through leaders
Albi, G.; Pareschi, L.; Zanella, M.
2014-01-01
The study of formations and dynamics of opinions leading to the so-called opinion consensus is one of the most important areas in mathematical modelling of social sciences. Following the Boltzmann-type control approach recently introduced by the first two authors, we consider a group of opinion leaders who modify their strategy accordingly to an objective functional with the aim of achieving opinion consensus. The main feature of the Boltzmann-type control is that, owing to an instantaneous binary control formulation, it permits the minimization of the cost functional to be embedded into the microscopic leaders’ interactions of the corresponding Boltzmann equation. The related Fokker–Planck asymptotic limits are also derived, which allow one to give explicit expressions of stationary solutions. The results demonstrate the validity of the Boltzmann-type control approach and the capability of the leaders’ control to strategically lead the followers’ opinion. PMID:25288820
Miniature Trailing Edge Effector for Aerodynamic Control
NASA Technical Reports Server (NTRS)
Lee, Hak-Tae (Inventor); Bieniawski, Stefan R. (Inventor); Kroo, Ilan M. (Inventor)
2008-01-01
Improved miniature trailing edge effectors for aerodynamic control are provided. Three types of devices having aerodynamic housings integrated to the trailing edge of an aerodynamic shape are presented, which vary in details of how the control surface can move. A bucket type device has a control surface which is the back part of a C-shaped member having two arms connected by the back section. The C-shaped section is attached to a housing at the ends of the arms, and is rotatable about an axis parallel to the wing trailing edge to provide up, down and neutral states. A flip-up type device has a control surface which rotates about an axis parallel to the wing trailing edge to provide up, down, neutral and brake states. A rotating type device has a control surface which rotates about an axis parallel to the chord line to provide up, down and neutral states.
Admittance Survey of Type 1 Coronae on Venus: Implications for Elastic Thickness
NASA Technical Reports Server (NTRS)
Hoogenboom, T.; Smrekar, S. E.; Anderson, F. S.; Houseman, G.
2003-01-01
Coronae are volcano-tectonic features on Venus which range from 60km to 2600km and are defined by their nearly circular patterns of fractures. Type 1 (regular) coronae are classified as having >50% complete fracture annuli. Previous work has examined the factors controlling the morphology, size, and fracture pattern of coronae, using lithospheric properties, loading signature and geologic characteristics. However, these studies have been limited to Type 2 (topographic) coronae (e.g. coronaes with <50% fracture annuli), and the factors controlling the formation of Type 1 coronae remain poorly understood. In this study, we apply the methodology of to survey the admittance signature for Type 1 coronae to determine the controlling parameters which govern Type 1 coronae formation.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Graber, P. Jameson, E-mail: jameson-graber@baylor.edu
We study a general linear quadratic mean field type control problem and connect it to mean field games of a similar type. The solution is given both in terms of a forward/backward system of stochastic differential equations and by a pair of Riccati equations. In certain cases, the solution to the mean field type control is also the equilibrium strategy for a class of mean field games. We use this fact to study an economic model of production of exhaustible resources.
Inhibitory control in bulimic-type eating disorders: a systematic review and meta-analysis.
Wu, Mudan; Hartmann, Mechthild; Skunde, Mandy; Herzog, Wolfgang; Friederich, Hans-Christoph
2013-01-01
The aim of this meta-analysis was to summarise data from neuropsychological studies on inhibitory control to general and disease-salient (i.e., food/eating, body/shape) stimuli in bulimic-type eating disorders (EDs). A systematic literature search was conducted to identify eligible experimental studies. The outcome measures studied included the performance on established inhibitory control tasks in bulimic-type EDs. Effect sizes (Hedges' g) were pooled using random-effects models. For inhibitory control to general stimuli, 24 studies were included with a total of 563 bulimic-type ED patients: 439 had bulimia nervosa (BN), 42 had anorexia nervosa of the binge/purge subtype (AN-b), and 82 had binge eating disorder (BED). With respect to inhibitory control to disease-salient stimuli, 12 studies were included, representing a total of 218 BN patients. A meta-analysis of these studies showed decreased inhibitory control to general stimuli in bulimic-type EDs (g = -0.32). Subgroup analysis revealed impairments with a large effect in the AN-b group (g = -0.91), impairments with a small effect in the BN group (g = -0.26), and a non-significant effect in the BED group (g = -0.16). Greater impairments in inhibitory control were observed in BN patients when confronted with disease-salient stimuli (food/eating: g = -0.67; body/shape: g = -0.61). In conclusion, bulimic-type EDs showed impairments in inhibitory control to general stimuli with a small effect size. There was a significantly larger impairment in inhibitory control to disease salient stimuli observed in BN patients, constituting a medium effect size.
Glycemic control and alveolar bone loss progression in type 2 diabetes.
Taylor, G W; Burt, B A; Becker, M P; Genco, R J; Shlossman, M
1998-07-01
This study tested the hypothesis that the risk for alveolar bone loss is greater, and bone loss progression more severe, for subjects with poorly controlled (PC) type 2 diabetes mellitus (type 2 DM) compared to those without type 2 DM or with better controlled (BC) type 2 DM. The PC group had glycosylated hemoglobin (HbA1) > or = 9%; the BC group had HbA1 < 9%. Data from the longitudinal study of the oral health of residents of the Gila River Indian Community were analyzed. Of the 359 subjects, aged 15 to 57 with less than 25% radiographic bone loss at baseline, 338 did not have type 2 DM, 14 were BC, and 7 were PC. Panoramic radiographs were used to assess interproximal bone level. Bone scores (scale 0-4) corresponding to bone loss of 0%, 1% to 24%, 25% to 49%, 50% to 74%, or > or = 75% were used to identify the worst bone score (WBS) in the dentition. Change in worst bone score at follow-up, the outcome, was specified on a 4-category ordinal scale as no change, or a 1-, 2-, 3-, or 4-category increase over baseline WBS (WBS1). Poorly controlled diabetes, age, calculus, time to follow-up examination, and WBS1 were statistically significant explanatory variables in ordinal logistic regression models. Poorly controlled type 2 DM was positively associated with greater risk for a change in bone score (compared to subjects without type 2 DM) when the covariates were included in the model. The cumulative odds ratio (COR) at each threshold of the ordered response was 11.4 (95% CI = 2.5, 53.3). When contrasted with subjects with BC type 2 DM, the COR for those in the PC group was 5.3 (95% CI = 0.8, 53.3). The COR for subjects with BC type 2 DM was 2.2 (95% CI = 0.7, 6.5), when contrasted to those without type 2 DM. These results suggest that poorer glycemic control leads to both an increased risk for alveolar bone loss and more severe progression over those without type 2 DM, and that there may be a gradient, with the risk for bone loss progression for those with better controlled type 2 DM intermediate to the other 2 groups.
Evaluation of central nervous system in patients with glycogen storage disease type 1a.
Aydemir, Yusuf; Gürakan, Figen; Saltık Temizel, İnci Nur; Demir, Hülya; Oğuz, Kader Karlı; Yalnızoğlu, Dilek; Topçu, Meral; Özen, Hasan; Yüce, Aysel
2016-01-01
We aimed to evaluate structure and functions of central nervous system (CNS) in children with glycogen storage disease (GSD) type 1a. Neurological examination, psychometric tests, electroencephalography (EEG), magnetic resonance imaging (MRI), visual evoked potentials (VEP) and brainstem auditory evoked potentials (BAEP) were performed. The results were compared between patients with good and poor metabolic control and healthy children. Twenty-three patients with GSD type 1a were studied. Twelve patients were in poor metabolic control group and 11 patients in good metabolic control group. Five patients had intellectual disability, 10 had EEG abnormalities, seven had abnormal VEP and two had abnormal BAEP results. MRI was abnormal in five patients. There was significant correlation between the number of hypoglycemic attacks and MRI abnormalities. Central nervous system may be affected in GSD type 1a even in patients with normal neurologic examination. Accumulation of abnormal results in patients with poor metabolic control supports the importance of metabolic control in GSD type 1a.
Colton, Patricia; Olmsted, Marion; Daneman, Denis; Rydall, Anne; Rodin, Gary
2004-07-01
To compare the prevalence of eating disturbances in preteen and early teenage girls with type 1 diabetes to their nondiabetic peers. A cross-sectional, case-controlled study of 101 girls with type 1 diabetes, ages 9-14 years, and 303 age-matched, female nondiabetic control subjects was conducted. Participants completed a Children's Eating Disorder Examination interview. Socioeconomic status, BMI, and diabetes-related variables were assessed. Groups were compared using chi(2) analyses. Binge eating; the use of intense, excessive exercise for weight control; the combination of two disturbed eating-related behaviors; and subthreshold eating disorders were all more common in girls with type 1 diabetes. Metabolic control was not related to eating behavior in this study population. Eating disturbances, though mostly mild, were significantly more common in preteen and early teenage girls with type 1 diabetes. Screening and prevention programs for this high-risk group should begin in the preteen years.
NASA Astrophysics Data System (ADS)
Wu, Bing-Fei; Ma, Li-Shan; Perng, Jau-Woei
This study analyzes the absolute stability in P and PD type fuzzy logic control systems with both certain and uncertain linear plants. Stability analysis includes the reference input, actuator gain and interval plant parameters. For certain linear plants, the stability (i.e. the stable equilibriums of error) in P and PD types is analyzed with the Popov or linearization methods under various reference inputs and actuator gains. The steady state errors of fuzzy control systems are also addressed in the parameter plane. The parametric robust Popov criterion for parametric absolute stability based on Lur'e systems is also applied to the stability analysis of P type fuzzy control systems with uncertain plants. The PD type fuzzy logic controller in our approach is a single-input fuzzy logic controller and is transformed into the P type for analysis. In our work, the absolute stability analysis of fuzzy control systems is given with respect to a non-zero reference input and an uncertain linear plant with the parametric robust Popov criterion unlike previous works. Moreover, a fuzzy current controlled RC circuit is designed with PSPICE models. Both numerical and PSPICE simulations are provided to verify the analytical results. Furthermore, the oscillation mechanism in fuzzy control systems is specified with various equilibrium points of view in the simulation example. Finally, the comparisons are also given to show the effectiveness of the analysis method.
Bolo, Nicolas R; Musen, Gail; Jacobson, Alan M; Weinger, Katie; McCartney, Richard L; Flores, Veronica; Renshaw, Perry F; Simonson, Donald C
2011-12-01
To investigate the effects of acute hypoglycemia on working memory and brain function in patients with type 1 diabetes. Using blood oxygen level-dependent (BOLD) functional magnetic resonance imaging during euglycemic (5.0 mmol/L) and hypoglycemic (2.8 mmol/L) hyperinsulinemic clamps, we compared brain activation response to a working-memory task (WMT) in type 1 diabetic subjects (n = 16) with that in age-matched nondiabetic control subjects (n = 16). Behavioral performance was assessed by percent correct responses. During euglycemia, the WMT activated the bilateral frontal and parietal cortices, insula, thalamus, and cerebellum in both groups. During hypoglycemia, activation decreased in both groups but remained 80% larger in type 1 diabetic versus control subjects (P < 0.05). In type 1 diabetic subjects, higher HbA(1c) was associated with lower activation in the right parahippocampal gyrus and amygdala (R(2) = 0.45, P < 0.002). Deactivation of the default-mode network (DMN) also was seen in both groups during euglycemia. However, during hypoglycemia, type 1 diabetic patients deactivated the DMN 70% less than control subjects (P < 0.05). Behavioral performance did not differ between glycemic conditions or groups. BOLD activation was increased and deactivation was decreased in type 1 diabetic versus control subjects during hypoglycemia. This higher level of brain activation required by type 1 diabetic subjects to attain the same level of cognitive performance as control subjects suggests reduced cerebral efficiency in type 1 diabetes.
2013-01-01
Background The Brazilian Study on the Practice of Diabetes Care main objective was to provide an epidemiological profile of individuals with type 1 and 2 diabetes mellitus (DM) in Brazil, concerning therapy and adherence to international guidelines in the medical practice. Methods This observational, cross-sectional, multicenter study collected and analyzed data from individuals with type 1 and 2 DM attending public or private clinics in Brazil. Each investigator included the first 10 patients with type 2 DM who visited his/her office, and the first 5 patients with type 1 DM. Results A total of 1,358 patients were analyzed; 375 (27.6%) had type 1 and 983 (72.4%) had type 2 DM. Most individuals were women, Caucasian, and private health care users. High prevalence rates of hypertension, dyslipidemia and central obesity were observed, particularly in type 2 DM. Only 7.3% and 5.1% of the individuals with types 1 and 2 DM, respectively, had optimal control of blood pressure, plasma glucose and lipids. The absence of hypertension and female sex were associated with better control of type 1 DM and other cardiovascular risk factors. In type 2 DM, older age was also associated with better control. Conclusions Female sex, older age, and absence of hypertension were associated with better metabolic control. An optimal control of plasma glucose and other cardiovascular risk factors are obtained only in a minority of individuals with diabetes. Local numbers, compared to those from other countries are worse. PMID:23972112
Thermann, Florian; Ukkat, Jörg; Wollert, Ulrich; Dralle, Henning; Brauckhoff, Michael
2007-11-01
Dialysis shunt-associated steal syndrome (DASS) is a rare complication of hemodialysis access (HA) which preferably occurs in brachial fistulas. Treatment options are discussed controversially. Aim of this study was to evaluate flow-controlled fistula banding. Patients treated between 2002 and 2006 were included in this prospective survey. According to a classification we established, patients were typed DASS I-III (I: short history, no dermal lesions; II: long history, skin lesions; III: long history, gangrene). Surgical therapy was HA banding including controlled reduction (about 50% of initial flow) of HA blood flow (patients type I and II). Patients with type III underwent closure of the HA. In 15 patients with relevant DASS, blood-flow-controlled banding was performed. In ten patients (all type I), banding led to restitution of the hand function while preserving the HA. In five patients (all type II), banding was not successful; in two patients, closure of the HA was performed eventually. In five patients (type III), primary closure of the HA was performed. Four patients with DASS type II but only two with DASS type I had diabetes mellitus (p = 0.006). Banding under blood flow control resulting in an approximately 50% reduction in the initial blood flow is an adequate therapeutic option in patients with brachial HA and type I-DASS. In type II-DASS, banding does not lead to satisfying results, more complex surgical options might be more successful. Diabetes is associated with poor HA outcome in case of DASS.
Saujanya, K; Prasad, M Ghanashyam; Sushma, B; Kumar, J Raghavendra; Reddy, Y S N; Niranjani, K
2016-01-01
Determining the relative risk of cleft lip and palate (CL[P]) on the basis of lip prints and dermatoglyphics as genetic background may be useful for genetic counseling, and the development of future preventive measures. (1) To analyze the various pattern types of lip prints and dermatoglyphics in parents of CL(P) children and to detect if any specific type can be contemplated as a genetic marker in the transmission of CL(P). (2) To compare these patterns with that of parents of unaffected children. 31 parents of children with CL(P) as a study group, and 31 parents of unaffected children as control group were included. Lip prints and finger prints were collected from all subjects and analysis of both patterns was carried out followed by a comparison of the patterns of unaffected parents with the controls statistically. Among the mothers of the study group, type O followed by type IIa lip patterns were found to be significantly higher in upper and lower lips, and in fathers type IIa followed by type O were significantly higher. In the control group, type IIb followed by type III were higher in both fathers and mothers. Dermatoglyphic analysis of palm and finger prints revealed no significant difference in the pattern types and total ridge counts, but the Atd angle asymmetry was found to be significant between study and control group. Types IIa and O lip patterns, asymmetry of Atd angles can be considered as genetic markers for the transmission of CL(P) deformity to offsprings.
Leeds, John S; Hadjivassiliou, Marios; Tesfaye, Solomon; Sanders, David S
2018-01-01
Lower gastrointestinal symptoms are not well characterized in people with type 1 diabetes, and the effects on quality of life and glycemic control are unknown. This study aimed to determine the prevalence of lower gastrointestinal symptoms and the effects on glycemic control and quality of life, and to investigate for underlying causes. This is a prospective, cohort study in secondary care. Patients with type 1 diabetes completed a gastrointestinal symptom questionnaire and the Short Form 36 V.2 quality of life questionnaire and had their hemoglobin A1c measured. Patients with diarrhea were offered reassessment and investigation as per the national guidelines. Controls without diabetes were used to compare symptom prevalence and quality of life scores. 706 with type 1 diabetes (mean age 41.9 years) and 604 controls (mean age 41.9 years) were enrolled. Gastrointestinal symptoms were significantly more frequent in type 1 diabetes compared with controls, in particular constipation (OR 2.4), diarrhea (OR 2.5), alternating bowel habit (OR 2.1), abdominal pain (OR 1.4), floating stools (OR 2.7), bloating (OR 1.4) and flatulence (OR 1.3) (all p<0.05). Previous pancreatitis was more frequent in type 1 diabetes (OR 4.6), but other gastrointestinal conditions were not. Gastrointestinal symptoms were associated with poorer glycemic control (p<0.01) and worse quality of life particularly in those with diarrhea. Investigation of those with diarrhea, including those with alternating bowel habit, (n=105), identified a cause in 72.3% with subsequent change in management. Gastrointestinal symptoms are twice as common in type 1 diabetes and associated with poorer quality of life and glycemic control. Investigation of diarrhea in people with type 1 diabetes leads to a high yield of treatable conditions and a change in management in about three-quarters.
Cheng, Shi-Hui; Ismail, Amin; Anthony, Joseph; Ng, Ooi Chuan; Hamid, Azizah Abdul; Yusof, Barakatun-Nisak Mohd
2016-02-27
Type 2 diabetes mellitus is a major health threat worldwide. Cosmos caudatus is one of the medicinal plants used to treat type 2 diabetes. Therefore, this study aims to determine the effectiveness and safety of C. caudatus in patients with type 2 diabetes. Metabolomic approach will be carried out to compare the metabolite profiles between C. Caudatus treated diabetic patients and diabetic controls. This is a single-center, randomized, controlled, two-arm parallel design clinical trial that will be carried out in a tertiary hospital in Malaysia. In this study, 100 patients diagnosed with type 2 diabetes will be enrolled. Diabetic patients who meet the eligibility criteria will be randomly allocated to two groups, which are diabetic C. caudatus treated(U) group and diabetic control (C) group. Primary and secondary outcomes will be measured at baseline, 4, 8, and 12 weeks. The serum and urine metabolome of both groups will be examined using proton NMR spectroscopy. The study will be the first randomized controlled trial to assess whether C. caudatus can confer beneficial effect in patients with type 2 diabetes. The results of this trial will provide clinical evidence on the effectiveness and safety of C. caudatus in patients with type 2 diabetes. ClinicalTrials.gov identifier: NCT02322268.
Yokomichi, Hiroshi; Nagai, Akiko; Hirata, Makoto; Kiyohara, Yutaka; Muto, Kaori; Ninomiya, Toshiharu; Matsuda, Koichi; Kamatani, Yoichiro; Tamakoshi, Akiko; Kubo, Michiaki; Nakamura, Yusuke; Yamagata, Zentaro
2017-03-01
Evidence of characteristics of Japanese patients with diabetes from a large-scale population is necessary. Few studies have compared glycaemic controls, complications and comorbidities between type 1 and 2 diabetic patients. This paper focuses on illustrating a clinical picture of Japanese diabetic patients and comparing glycaemic control and prognoses between type 1 and 2 diabetes using multi-institutional data. The BioBank Japan Project enrolled adult type 1 and 2 diabetic patients between fiscal years 2003 and 2007. We have presented characteristics, controls of serum glucose, cholesterol and blood pressure, prevalence of complications and comorbidities and survival curves. We have also shown glycaemic controls according to various individual profiles of diabetic patients. A total of 558 type 1 diabetic patients and 30,834 type 2 diabetic patients participated in this study. The mean glycated haemoglobin A1c was higher in type 1 diabetes than in type 2 diabetes. In the type 1 diabetic patients, the glycated haemoglobin A1c had no consistent trend according to age and body mass index. The Kaplan-Meier estimates represented a longer survival time from baseline with type 1 diabetes than with type 2 diabetes. Compared with type 1 diabetic patients, type 2 diabetic patients had double the prevalence of macrovascular complications. This work has revealed detailed plasma glucose levels of type 1 and 2 diabetic patients according to age, body mass index, blood pressure, serum cholesterol levels and smoking and drinking habits. Our data have also shown that the prognosis is worse for type 2 diabetes than for type 1 diabetes in Japan. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.
Plasma and Muscle Myostatin in Relation to Type 2 Diabetes
Brandt, Claus; Nielsen, Anders R.; Fischer, Christian P.; Hansen, Jakob; Pedersen, Bente K.; Plomgaard, Peter
2012-01-01
Objective Myostatin is a secreted growth factor expressed in skeletal muscle tissue, which negatively regulates skeletal muscle mass. Recent animal studies suggest a role for myostatin in insulin resistance. We evaluated the possible metabolic role of myostatin in patients with type 2 diabetes and healthy controls. Design 76 patients with type 2 diabetes and 92 control subjects were included in the study. They were matched for age, gender and BMI. Plasma samples and biopsies from the vastus lateralis muscle were obtained to assess plasma myostatin and expression of myostatin in skeletal muscle. Results Patients with type 2 diabetes had higher fasting glucose (8.9 versus 5.1 mmol/L, P<0.001), plasma insulin (68.2 versus 47.2 pmol/L, P<0.002) and HOMA2-IR (1.6 versus 0.9, P<0.0001) when compared to controls. Patients with type 2 diabetes had 1.4 (P<0.01) higher levels of muscle myostatin mRNA content than the control subjects. Plasma myostatin concentrations did not differ between patients with type 2 diabetes and controls. In healthy controls, muscle myostatin mRNA correlated with HOMA2-IR (r = 0.30, P<0.01), plasma IL-6 (r = 0.34, P<0.05) and VO2 max (r = −0.26, P<0.05), however, no correlations were observed in patients with type 2 diabetes. Conclusions This study supports the idea that myostatin may have a negative effect on metabolism. However, the metabolic effect of myostatin appears to be overruled by other factors in patients with type 2 diabetes. PMID:22615949
Scholes, Cheryl; Mandleco, Barbara; Roper, Susanne; Dearing, Karen; Dyches, Tina; Freeborn, Donna
2013-06-01
To explore if young people with higher and lower levels of metabolic control of type 1 diabetes have different perceptions about their lives and illness. Adolescence through emerging adulthood is a developmental stage made more challenging when the person has type 1 diabetes. Little research has investigated if individuals with high and low levels of metabolic control in this age group perceive their disease differently. Qualitative descriptive. In this study, 14 participants, ages 11-22 years were interviewed in 2008 about their perceptions of living with type 1 diabetes. Through a process of induction, major themes were identified. Participants with high and low metabolic control levels reported similar themes related to reactions of others, knowledge about type 1 diabetes, and believed healthcare providers used authoritarian interactions. However, high metabolic control level participants believed type 1 diabetes would be cured; had negative initial responses to being diagnosed; rarely received parental support in managing their diabetes; and were negligent in self-care activities. Participants with low metabolic control levels did not believe a cure was imminent or have negative responses to being diagnosed; received parental support in managing diabetes; and were diligent in self-care activities. Nurses should give information to young people with type 1 diabetes beyond initial diagnosis and help and support this age group learn appropriate ways to manage their disease, develop positive relationships with healthcare professionals, and participate in interactions with others their age successfully managing type 1 diabetes. © 2012 Blackwell Publishing Ltd.
Synthesis of robust nonlinear autopilots using differential game theory
NASA Technical Reports Server (NTRS)
Menon, P. K. A.
1991-01-01
A synthesis technique for handling unmodeled disturbances in nonlinear control law synthesis was advanced using differential game theory. Two types of modeling inaccuracies can be included in the formulation. The first is a bias-type error, while the second is the scale-factor-type error in the control variables. The disturbances were assumed to satisfy an integral inequality constraint. Additionally, it was assumed that they act in such a way as to maximize a quadratic performance index. Expressions for optimal control and worst-case disturbance were then obtained using optimal control theory.
Focal Length Controllable Ultrasonic Transducer Using Bimorph-Type Bending Actuator
NASA Astrophysics Data System (ADS)
Chae, Min-Ku; Kim, Moo-Joon; Ha, Kang-Lyeol; Lee, Chai-Bong
2003-05-01
Using a bimorph-type bending actuator, we propose a new method for controlling the focal length of a transducer by electric DC voltage. We designed two focal length controllable ultrasonic transducers with actuators, a line-focus and a point-focus transducer. The polyvinylidene fluoride (PVDF) piezoelectric type polymer film is used for transmitting and receiving of ultrasonic signals. Using the new method, it is confirmed by investigation of the underwater acoustic field that the focal length can be controlled to within 10% of the radius of the transducer curvature.
Effects of a group rational-emotive behavior therapy program on the Type A behavior pattern.
Möller, A T; Botha, H C
1996-06-01
A sample of 44 male Type A insurance representatives, selected by means of the Videotaped Structured Interview, were randomly assigned to a treatment (n = 22) and a delayed treatment control group (n = 22). The treatment group participated in 9 weekly sessions of group Rational-Emotive Behavior Therapy and were followed up after 10 weeks. After the control period, the delayed treatment control group received the same treatment program. Repeated measurements were obtained by means of the Videotaped Structured Interview, Jenkins Activity Survey, Cook-Medley Hostility Scale, and Type A Cognitive Questionnaire. Self and spouse/friend ratings of Type A behavior were obtained by means of the Bortner Rating Scale. Analysis indicated that, compared to the control condition, the therapy significantly reduced the intensity of Type A behavior and its time urgency component. These improvements were maintained at follow-up and were accompanied by self-reports of significant positive changes in Type A behavior and irrational beliefs.
Codimension-Two Bifurcation, Chaos and Control in a Discrete-Time Information Diffusion Model
NASA Astrophysics Data System (ADS)
Ren, Jingli; Yu, Liping
2016-12-01
In this paper, we present a discrete model to illustrate how two pieces of information interact with online social networks and investigate the dynamics of discrete-time information diffusion model in three types: reverse type, intervention type and mutualistic type. It is found that the model has orbits with period 2, 4, 6, 8, 12, 16, 20, 30, quasiperiodic orbit, and undergoes heteroclinic bifurcation near 1:2 point, a homoclinic structure near 1:3 resonance point and an invariant cycle bifurcated by period 4 orbit near 1:4 resonance point. Moreover, in order to regulate information diffusion process and information security, we give two control strategies, the hybrid control method and the feedback controller of polynomial functions, to control chaos, flip bifurcation, 1:2, 1:3 and 1:4 resonances, respectively, in the two-dimensional discrete system.
Fabrication of 4H-SiC PiN diodes without bipolar degradation by improved device processes
NASA Astrophysics Data System (ADS)
Bu, Yuan; Yoshimoto, Hiroyuki; Watanabe, Naoki; Shima, Akio
2017-12-01
We developed a simple technology for fabricating bipolar degradation-free 6.5 kV SiC PiN diodes on the basal plane dislocation (BPD)-free areas of commercially available 4H-SiC wafers. In order to suppress process-induced basal plane dislocation, we first investigated the causes of BPD generation during fabrication and then improved the processes. We found that no BPD was induced on a flat Si-face, but a large number of BPDs were concentrated in the mesa edge after high-dose Al ions were implanted [p++ ion implantation (I. I.)] at room temperature (RT) followed by activation annealing. Therefore, we examined new technologies in device processes including (I) long-term high-temperature oxidation after the mesa process to remove etching damage in the mesa edge and (II) reducing the Al dose (p+ I. I.) in the mesa edge to suppress BPD generation. We investigated the effect of the Al dose in the mesa edge on BPD generation and bipolar degradation. The results indicated that no BPD appeared when the dose was lower than 1 × 1015 atoms/cm2 and when long-term high-temperature oxidation was applied after the mesa process. As a result, we successfully fabricated 6.5 kV PiN diodes without bipolar degradation on BPD-free areas. Moreover, the diodes are very stable when applying 270 A/cm2 for over 100 h. Photoluminescence (PL) observation indicated that no BPD was generated during the improved fabrication processes. Besides, the Ir-Vr measurements showed that the breakdown voltage was over 8 kV at RT. The leakage currents are as low as 7.6 × 10-5 mA/cm2 (25 °C) and 6.3 × 10-4 mA/cm2 (150 °C) at 6.5 kV. Moreover, this result is applicable not only for PiN diodes but also for MOSFETs (body diode), IGBTs, thyristors, etc.
Effects of morphological control on the characteristics of vertical-type OTFTs using Alq3.
Kim, Young Do; Park, Jong Wook; Kang, In Nam; Oh, Se Young
2008-09-01
We have fabricated vertical-type organic thin-film transistors (OTFTs) using tris-(8-hydroxyquinoline) aluminum (Alq(3)) as an n-type active material. Vertical-type OTFT using Alq(3) has a layered structure of Al(source electrode)/Alq(3)(active layer)/Al(gate electrode)/Alq(3)(active layer)/ITO glass(drain electrode). Alq(3) thin films containing various surface morphologies could be obtained by the control of evaporation rate and substrate temperature. The effects of the morphological control of Alq(3) thin layer on the grain size and the flatness of film surface were investigated. The characteristics of vertical-type OTFT significantly influenced the growth condition of Alq(3) layer.
NASA Astrophysics Data System (ADS)
Postnov, Sergey
2017-11-01
Two kinds of optimal control problem are investigated for linear time-invariant fractional-order systems with lumped parameters which dynamics described by equations with Hadamard-type derivative: the problem of control with minimal norm and the problem of control with minimal time at given restriction on control norm. The problem setting with nonlocal initial conditions studied. Admissible controls allowed to be the p-integrable functions (p > 1) at half-interval. The optimal control problem studied by moment method. The correctness and solvability conditions for the corresponding moment problem are derived. For several special cases the optimal control problems stated are solved analytically. Some analogies pointed for results obtained with the results which are known for integer-order systems and fractional-order systems describing by equations with Caputo- and Riemann-Liouville-type derivatives.
Salivary flow rate and xerostomia in patients with type I and II diabetes mellitus
Hoseini, Amineh; Mirzapour, Ali; Bijani, Ali; Shirzad, Atena
2017-01-01
Background Diabetes mellitus is one of the most prevalent metabolic diseases, with complications such as decreased salivary flow rate and xerostomia. Objective This study aimed to determine the salivary flow rate and xerostomia in type I and II diabetic patients in comparison with healthy controls. Methods This case-control study was performed on diabetic patients of a private office in Babol, Iran, between May 2015 and October 2016. This study involved two study groups (type I and II diabetes, with 40 in each group) and two control groups (control I and II, with 35 in each group) which were age- and sex-matched with the related study groups. They were all selected through simple sampling. Unstimulated whole saliva was collected through Navazesh method and the salivary flow rate was measured (ml/min). Xerostomia was evaluated via Fox’s test. Moreover, the patients’ data were recorded including age, sex, disease duration, type of diabetes, fasting blood glucose (FBG) and HbA1C. The obtained data were statistically analyzed by using SPSS version 17. Independent-samples t-test, Chi-square, Pearson correlation and multiple comparison post-hoc tests were employed as appropriated. p<0.05 was considered significant. Results The mean salivary flow rate in type I diabetics (0.35±0.11 ml/min) was lower than that in control I (0.50±0.07 ml/min) (p=0.01). The same difference was observed between type II diabetics (0.37±0.13 ml/min) and control II groups (0.47±0.11 ml/min) (p=0.01). No significant difference was observed in the salivary flow rate between type I and II diabetics (p=0.345). Furthermore, xerostomia was higher in type I (2.70±2.50, 1.17±1.60) and II (2.65±2.20–1.62±1.50) diabetics compared with the related control groups (p=0.01), (p=0.02). Conclusion Type I, II diabetic patients revealed lower salivary flow rate and higher xerostomia compared with healthy controls. The salivary flow rate and xerostomia had inverse correlation. PMID:29038704
Salivary flow rate and xerostomia in patients with type I and II diabetes mellitus.
Hoseini, Amineh; Mirzapour, Ali; Bijani, Ali; Shirzad, Atena
2017-09-01
Diabetes mellitus is one of the most prevalent metabolic diseases, with complications such as decreased salivary flow rate and xerostomia. This study aimed to determine the salivary flow rate and xerostomia in type I and II diabetic patients in comparison with healthy controls. This case-control study was performed on diabetic patients of a private office in Babol, Iran, between May 2015 and October 2016. This study involved two study groups (type I and II diabetes, with 40 in each group) and two control groups (control I and II, with 35 in each group) which were age- and sex-matched with the related study groups. They were all selected through simple sampling. Unstimulated whole saliva was collected through Navazesh method and the salivary flow rate was measured (ml/min). Xerostomia was evaluated via Fox's test. Moreover, the patients' data were recorded including age, sex, disease duration, type of diabetes, fasting blood glucose (FBG) and HbA1C. The obtained data were statistically analyzed by using SPSS version 17. Independent-samples t-test, Chi-square, Pearson correlation and multiple comparison post-hoc tests were employed as appropriated. p<0.05 was considered significant. The mean salivary flow rate in type I diabetics (0.35±0.11 ml/min) was lower than that in control I (0.50±0.07 ml/min) (p=0.01). The same difference was observed between type II diabetics (0.37±0.13 ml/min) and control II groups (0.47±0.11 ml/min) (p=0.01). No significant difference was observed in the salivary flow rate between type I and II diabetics (p=0.345). Furthermore, xerostomia was higher in type I (2.70±2.50, 1.17±1.60) and II (2.65±2.20-1.62±1.50) diabetics compared with the related control groups (p=0.01), (p=0.02). Type I, II diabetic patients revealed lower salivary flow rate and higher xerostomia compared with healthy controls. The salivary flow rate and xerostomia had inverse correlation.
29 CFR 1910.1026 - Chromium (VI).
Code of Federal Regulations, 2012 CFR
2012-07-01
... resembling the processes, types of material, control methods, work practices, and environmental conditions in... resembling the processes, types of material, control methods, work practices, and environmental conditions in..., work practices, or control methods that may result in new or additional exposures to chromium (VI), or...
29 CFR 1910.1026 - Chromium (VI).
Code of Federal Regulations, 2014 CFR
2014-07-01
... resembling the processes, types of material, control methods, work practices, and environmental conditions in... resembling the processes, types of material, control methods, work practices, and environmental conditions in..., work practices, or control methods that may result in new or additional exposures to chromium (VI), or...
49 CFR 1180.2 - Types of transactions.
Code of Federal Regulations, 2010 CFR
2010-10-01
... OF TRANSPORTATION RULES OF PRACTICE RAILROAD ACQUISITION, CONTROL, MERGER, CONSOLIDATION PROJECT... types: Major, significant, minor, and exempt. (a) A major transaction is a control or merger involving... control or merger of two or more class I railroads that is of regional or national transportation...
Typing for Conflict Detection in Access Control Policies
NASA Astrophysics Data System (ADS)
Adi, Kamel; Bouzida, Yacine; Hattak, Ikhlass; Logrippo, Luigi; Mankovskii, Serge
In this paper we present an access control model that considers both abstract and concrete access control policies specifications. Permissions and prohibitions are expressed within this model with contextual conditions. This situation may lead to conflicts. We propose a type system that is applied to the different rules in order to check for inconsistencies. If a resource is well typed, it is guaranteed that access rules to the resource contain no conflicts.
Tsukamoto, Akira; Higashiyama, Satoru; Yoshida, Kenji; Watanabe, Yoshiaki; Furukawa, Katsuko S; Ushida, Takashi
2011-12-01
An increase in cytoplasmic calcium (Ca(2+) increase) is a second messenger that is often observed under ultrasound irradiation. We hypothesize that cavitation is a physical mechanism that underlies the increase in Ca(2+) in these experiments. To control the presence of cavitation, the wave type was controlled in a sonication chamber. One wave type largely contained a traveling wave (wave type A) while the other wave type largely contained a standing wave (wave type B). Fast Fourier transform (FFT) analysis of a sound field produced by the wave types ascertained that stable cavitation was present only under wave type A ultrasound irradiation. Under the two controlled wave types, the increase in Ca(2+) in L929 fibroblasts was observed with fluorescence imaging. Under wave type A ultrasound irradiation, an increase in Ca(2+) was observed; however, no increase in Ca(2+) was observed under wave type B ultrasound irradiation. We conclude that stable cavitation is involved in the increase of Ca(2+) in cells subjected to pulsed ultrasound. Copyright © 2011 Elsevier B.V. All rights reserved.
Controlling the type and the form of chip when machining steel
NASA Astrophysics Data System (ADS)
Gruby, S. V.; Lasukov, A. A.; Nekrasov, R. Yu; Politsinsky, E. V.; Arkhipova, D. A.
2016-08-01
The type of the chip produced in the process of machining influences many factors of production process. Controlling the type of chip when cutting metals is important for producing swarf chips and for easing its utilization as well as for protecting the machined surface, cutting tool and the worker. In the given work we provide the experimental data on machining structural steel with implanted tool. The authors show that it is possible to control the chip formation process to produce the required type of chip by selecting the material for machining the tool surface.
Investigation of orbitofrontal sulcogyral pattern in chronic schizophrenia.
Cropley, Vanessa L; Bartholomeusz, Cali F; Wu, Peter; Wood, Stephen J; Proffitt, Tina; Brewer, Warrick J; Desmond, Patricia M; Velakoulis, Dennis; Pantelis, Christos
2015-11-30
Abnormalities of orbitofrontal cortex (OFC) pattern type distribution have been associated with schizophrenia-spectrum disorders. We investigated OFC pattern type in a large sample of chronic schizophrenia patients and healthy controls. We found an increased frequency of Type II but no difference in Type I or III folding pattern in the schizophrenia group in comparison to controls. Further large studies are required to investigate the diagnostic specificity of altered OFC pattern type and to confirm the distribution of pattern type in the normal population. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
ERIC Educational Resources Information Center
Ellis, Deborah A.; Templin, Thomas; Naar-King, Sylvie; Frey, Maureen A.; Cunningham, Phillippe B.; Podolski, Cheryl-Lynn; Cakan, Nedim
2007-01-01
The primary purpose of the present study was to determine whether multisystemic therapy (MST), an intensive, home-based psychotherapy, improved regimen adherence, metabolic control, and rates of hospitalization for diabetic ketoacidosis (DKA) among adolescents with chronically poorly controlled Type 1 diabetes 6 months after the completion of…
Detailed Investigation of the Role of Common and Low-Frequency WFS1 Variants in Type 2 Diabetes Risk
Fawcett, Katherine A.; Wheeler, Eleanor; Morris, Andrew P.; Ricketts, Sally L.; Hallmans, Göran; Rolandsson, Olov; Daly, Allan; Wasson, Jon; Permutt, Alan; Hattersley, Andrew T.; Glaser, Benjamin; Franks, Paul W.; McCarthy, Mark I.; Wareham, Nicholas J.; Sandhu, Manjinder S.; Barroso, Inês
2010-01-01
OBJECTIVE Wolfram syndrome 1 (WFS1) single nucleotide polymorphisms (SNPs) are associated with risk of type 2 diabetes. In this study we aimed to refine this association and investigate the role of low-frequency WFS1 variants in type 2 diabetes risk. RESEARCH DESIGN AND METHODS For fine-mapping, we sequenced WFS1 exons, splice junctions, and conserved noncoding sequences in samples from 24 type 2 diabetic case and 68 control subjects, selected tagging SNPs, and genotyped these in 959 U.K. type 2 diabetic case and 1,386 control subjects. The same genomic regions were sequenced in samples from 1,235 type 2 diabetic case and 1,668 control subjects to compare the frequency of rarer variants between case and control subjects. RESULTS Of 31 tagging SNPs, the strongest associated was the previously untested 3′ untranslated region rs1046320 (P = 0.008); odds ratio 0.84 and P = 6.59 × 10−7 on further replication in 3,753 case and 4,198 control subjects. High correlation between rs1046320 and the original strongest SNP (rs10010131) (r2 = 0.92) meant that we could not differentiate between their effects in our samples. There was no difference in the cumulative frequency of 82 rare (minor allele frequency [MAF] <0.01) nonsynonymous variants between type 2 diabetic case and control subjects (P = 0.79). Two intermediate frequency (MAF 0.01–0.05) nonsynonymous changes also showed no statistical association with type 2 diabetes. CONCLUSIONS We identified six highly correlated SNPs that show strong and comparable associations with risk of type 2 diabetes, but further refinement of these associations will require large sample sizes (>100,000) or studies in ethnically diverse populations. Low frequency variants in WFS1 are unlikely to have a large impact on type 2 diabetes risk in white U.K. populations, highlighting the complexities of undertaking association studies with low-frequency variants identified by resequencing. PMID:20028947
On controlling networks of limit-cycle oscillators
NASA Astrophysics Data System (ADS)
Skardal, Per Sebastian; Arenas, Alex
2016-09-01
The control of network-coupled nonlinear dynamical systems is an active area of research in the nonlinear science community. Coupled oscillator networks represent a particularly important family of nonlinear systems, with applications ranging from the power grid to cardiac excitation. Here, we study the control of network-coupled limit cycle oscillators, extending the previous work that focused on phase oscillators. Based on stabilizing a target fixed point, our method aims to attain complete frequency synchronization, i.e., consensus, by applying control to as few oscillators as possible. We develop two types of controls. The first type directs oscillators towards larger amplitudes, while the second does not. We present numerical examples of both control types and comment on the potential failures of the method.
Opuntia Extract Reduces Scar Formation in Rabbit Ear Model: A Randomized Controlled Study.
Fang, Quan; Huang, Chunlan; You, Chuangang; Ma, Shaolin
2015-12-01
The purpose of this article is to investigate the effect of Opuntia stricta H (Cactaceae) extract on suppression of hypertrophic scar on ventral surface wounds of rabbit ears. Full thickness skin defection was established in a rabbit ear to simulate hypertrophic scar. Opuntia extract was sprayed on the wounds in the experimental group, and normal saline was used in the control group. After the wounds healed with scar formation, the hypertrophic scar tissue was harvested on days 22, 39, and 54 for histological analysis. The expression of type I and type III collagen and matrix metalloproteinase-1 (MMP-1) were evaluated by immunohistochemistry and real-time quantitative polymerase chain reaction. The results indicated that the scar of the control group is more prominent compared with the opuntia extract group. The expression of type I collagen in the opuntia extract group was lower than the control group, while type III collagen in opuntia extract group gradually increased and exceeded control group. The expression of MMP-1 decreased in the opuntia extract group, while the control group increased over time, but the amount of MMP-1 was much higher than that in the control group on day 22. In conclusion, opuntia extract reduces hypertrophic scar formation by means of type I collagen inhibition, and increasing type III collagen and MMP-1.T he novel application of opuntia extract may lead to innovative and effective antiscarring therapies. © The Author(s) 2015.
Juang, Chia-Feng; Hsu, Chia-Hung
2009-12-01
This paper proposes a new reinforcement-learning method using online rule generation and Q-value-aided ant colony optimization (ORGQACO) for fuzzy controller design. The fuzzy controller is based on an interval type-2 fuzzy system (IT2FS). The antecedent part in the designed IT2FS uses interval type-2 fuzzy sets to improve controller robustness to noise. There are initially no fuzzy rules in the IT2FS. The ORGQACO concurrently designs both the structure and parameters of an IT2FS. We propose an online interval type-2 rule generation method for the evolution of system structure and flexible partitioning of the input space. Consequent part parameters in an IT2FS are designed using Q -values and the reinforcement local-global ant colony optimization algorithm. This algorithm selects the consequent part from a set of candidate actions according to ant pheromone trails and Q-values, both of which are updated using reinforcement signals. The ORGQACO design method is applied to the following three control problems: 1) truck-backing control; 2) magnetic-levitation control; and 3) chaotic-system control. The ORGQACO is compared with other reinforcement-learning methods to verify its efficiency and effectiveness. Comparisons with type-1 fuzzy systems verify the noise robustness property of using an IT2FS.
NASA Technical Reports Server (NTRS)
Platt, Robert (Inventor); Wampler, II, Charles W. (Inventor); Abdallah, Muhammad E. (Inventor)
2013-01-01
A robotic system includes a robot having manipulators for grasping an object using one of a plurality of grasp types during a primary task, and a controller. The controller controls the manipulators during the primary task using a multiple-task control hierarchy, and automatically parameterizes the internal forces of the system for each grasp type in response to an input signal. The primary task is defined at an object-level of control, e.g., using a closed-chain transformation, such that only select degrees of freedom are commanded for the object. A control system for the robotic system has a host machine and algorithm for controlling the manipulators using the above hierarchy. A method for controlling the system includes receiving and processing the input signal using the host machine, including defining the primary task at the object-level of control, e.g., using a closed-chain definition, and parameterizing the internal forces for each of grasp type.
Domain-specific conflict adaptation without feature repetitions.
Akçay, Çağlar; Hazeltine, Eliot
2011-06-01
An influential account of how cognitive control deals with conflicting sources of information holds that conflict is monitored by a module that automatically recruits attention to resolve the conflict. This leads to reduced effects of conflict on the subsequent trial, a phenomenon termed conflict adaptation. A prominent question is whether control processes are domain specific--that is, recruited only by the particular type of conflict they resolve. Previous studies that have examined this question used two-choice tasks in which feature repetition effects could be responsible for domain-specific adaptation effects. We report two experiments using four-choice (Experiment 1) and five-choice (Experiment 2) tasks that contain two types of irrelevant sources of potentially conflicting information: stimulus location (Simon conflict) and distractors (flanker conflict). In both experiments, we found within-type conflict adaptation for both types of conflict after eliminating trials on which stimulus features were repeated from one trial to the next. Across-type conflict adaptation, however, was not significant. Thus, conflict adaptation was due to domain-specific recruitment of cognitive control. Our results add converging evidence to the idea that multiple independent control processes are involved in reactive cognitive control, although whether control is always local remains to be determined.
Holm, Anja; Bang-Berthelsen, Claus Heiner; Knudsen, Stine; Kornum, Birgitte R.; Modvig, Signe; Jennum, Poul; Gammeltoft, Steen
2014-01-01
Study Objectives: MicroRNAs (miRNAs) have been implicated in the pathogenesis of human diseases including neurological disorders. The aim is to address the involvement of miRNAs in the pathophysiology of central hypersomnias including autoimmune narcolepsy with cataplexy and hypocretin deficiency (type 1 narcolepsy), narcolepsy without cataplexy (type 2 narcolepsy), and idiopathic hypersomnia. Design: We conducted high-throughput analysis of miRNA in plasma from three groups of patients—with type 1 narcolepsy, type 2 narcolepsy, and idiopathic hypersomnia, respectively—in comparison with healthy controls using quantitative real-time polymerase chain reaction (qPCR) panels. Setting: University hospital based sleep clinic and research laboratories. Patients: Twelve patients with type 1 narcolepsy, 12 patients with type 2 narcolepsy, 12 patients with idiopathic hypersomnia, and 12 healthy controls. Measurements and Results: By analyzing miRNA in plasma with qPCR we identified 50, 24, and 6 miRNAs that were different in patients with type 1 narcolepsy, type 2 narcolepsy, and idiopathic hypersomnia, respectively, compared with healthy controls. Twenty miRNA candidates who fulfilled the criteria of at least two-fold difference and p-value < 0.05 were selected to validate the miRNA changes in an independent cohort of patients. Four miRNAs differed significantly between type 1 narcolepsy patients and healthy controls. Levels of miR-30c, let-7f, and miR-26a were higher, whereas the level of miR-130a was lower in type 1 narcolepsy than healthy controls. The miRNA differences were not specific for type 1 narcolepsy, since the levels of the four miRNAs were also altered in patients with type 2 narcolepsy and idiopathic hypersomnia compared with healthy controls. Conclusion: The levels of four miRNAs differed in plasma from patients with type 1 narcolepsy, type 2 narcolepsy and idiopathic hypersomnia suggesting that alterations of miRNAs may be involved in the pathophysiology of central hypersomnias. Citation: Holm A, Bang-Berthelsen CH, Knudsen S, Kornum BR, Modvig S, Jennum P, Gammeltoft S. miRNA profiles in plasma from patients with sleep disorders reveal dysregulation of miRNAs in narcolepsy and other central hypersomnias. SLEEP 2014;37(9):1525-1533. PMID:25142559
Prevalence of xerostomia and the salivary flow rate in diabetic patients.
Malicka, Barbara; Kaczmarek, Urszula; Skośkiewicz-Malinowska, Katarzyna
2014-01-01
Diabetes is a metabolic disease characterized by hyperglycemia, which results from relative or absolute insulin deficiency. One of the first oral symptoms of diabetes is xerostomia. The aim of the study was to determine the prevalence of the xerostomia symptoms and salivary flow rate in diabetic patients according to the type of diabetes, the level of metabolic control and the duration of the disease. The study involved 156 adult patients of both sexes including 34 patients with diabetes type 1 (group C1), 59 with diabetes type 2 (group C2), and 63 generally healthy individuals as two control groups, sex- and age-matched to the diabetic group. The patients suffering from both types of diabetes were additionally subdivided according to the level of metabolic control and the duration of the disease. Xerostomia was diagnosed with the use of a specially prepared questionnaire and Fox's test. Moreover, the salivary flow rate of resting mixed saliva was measured. In type 1 diabetics, a significantly lower salivary flow rate in comparison to the age-matched control group (0.38 ± 0.19 mL/min vs. 0.53 ± 0.20 mL/min, p < 0.01) was found. However in type 2 diabetics, a slight lower salivary flow rate was noticed (on average, 20% lower). Dry mouth was far more frequently diagnosed in type 1 diabetics than in the control group. In type 1 diabetics, in comparison to healthy subjects, a significantly lower resting flow rate of saliva and significantly higher prevalence of xerosomia were observed, but in type 2 diabetics, only a trend of such variability was observed.
Broadbent, Elizabeth; Donkin, Liesje; Stroh, Julia C
2011-02-01
To investigate diabetic patients' perceptions of illness and treatments, and explore relationships to adherence and blood glucose control. Forty-nine type 1 and one hundred and eight type 2 diabetic patients completed questionnaires assessing illness perceptions, treatment beliefs, and adherence to medications, diet, and exercise. Blood glucose control was assessed from blood tests. Patients rated medication more important than diet and exercise, and reported higher adherence to medications. Insulin was perceived as more helpful for diabetes, while antihypertensives and cholesterol medication were perceived more helpful for preventing heart problems. Perceptions were associated with adherence to insulin, cholesterol and antihypertensive medications, exercise, and diet. Blood glucose control in type 1 diabetic patients was associated with insulin adherence and perceived personal control, and in type 2 diabetic patients to being prescribed insulin or antihypertensives, and perceived personal control. Patients hold specific mental models about diabetes treatments, which are associated with adherence.
Hannerz, Jan; Schnell, P-O; Larsson, Stig; Jacobsson, Hans
2004-03-01
To investigate the mechanisms behind the increase of chronic tension-type headache during head-down tilt. The pathophysiology of chronic tension-type headache is unknown. Ten patients suffering from chronic tension-type headache and 10 age- and sex-matched controls were studied with respect to pain intensity and alterations in cranial blood volume using planar scintigraphy and radiolabeled autologous erythrocytes before, during, and after head-down tilt, a procedure known to increase chronic tension-type headache. Four of 8 patients with chronic tension-type headache studied had increased cerebrospinal fluid pressure. During head-down tilt, the pain increased significantly in the group with chronic tension-type headache (P <.001) while the procedure did not cause headache in the controls. Blood volume significantly increased extracranially and decreased intracranially in both groups during head-down tilt. The extracranial nasal blood volume was significantly related to the pain experienced by the patients with chronic tension-type headache before and during head-down tilt. Although the changes in blood volume and, presumably, the increase of intracranial pressure were similar in the patients with chronic tension-type headache and the controls, only the patients experienced pain and pain increase during head-down tilt. This indicates that the pre-head-down tilt conditions must be different in the 2 groups and should be related to increased cerebrospinal fluid pressure/intracranial venous pressure in patients with chronic tension-type headache compared with controls. A difference in central mechanisms may, however, also be of importance for the difference in headache provocation in the 2 groups during head-down tilt.
NASA Astrophysics Data System (ADS)
Bakri, F. A.; Mashor, M. Y.; Sharun, S. M.; Bibi Sarpinah, S. N.; Abu Bakar, Z.
2016-10-01
This study proposes an adaptive fuzzy controller for attitude control system (ACS) of Innovative Satellite (InnoSAT) based on direct action type structure. In order to study new methods used in satellite attitude control, this paper presents three structures of controllers: Fuzzy PI, Fuzzy PD and conventional Fuzzy PID. The objective of this work is to compare the time response and tracking performance among the three different structures of controllers. The parameters of controller were tuned on-line by adjustment mechanism, which was an approach similar to a PID error that could minimize errors between actual and model reference output. This paper also presents a Model References Adaptive Control (MRAC) as a control scheme to control time varying systems where the performance specifications were given in terms of the reference model. All the controllers were tested using InnoSAT system under some operating conditions such as disturbance, varying gain, measurement noise and time delay. In conclusion, among all considered DA-type structures, AFPID controller was observed as the best structure since it outperformed other controllers in most conditions.
Genetics of Lesch's typology of alcoholism.
Samochowiec, Jerzy; Kucharska-Mazur, Jolanta; Grzywacz, Anna; Pelka-Wysiecka, Justyna; Mak, Monika; Samochowiec, Agnieszka; Bienkowski, Przemyslaw
2008-02-15
It is widely accepted that dopamine and serotonin (5-HT) neurotransmission can be critically involved in the development of alcohol abuse and alcohol dependence. Lesch's typology of alcoholism has been gaining increasing popularity as it qualitatively differentiates patients into different treatment response subgroups. The aim of the present study was to evaluate a possible genetic background of Lesch's typology with special emphasis placed on dopamine- and serotonin-related genes. 122 alcoholics (the mean age: 35+/-9 years) were investigated. According to Lesch's typology, 58 patients were of type I, 36 patients of type II, 11 patients of type III, and 17 patients of type IV. Alcohol drinking and family history was assessed by means of a structured interview, based on the Semi-Structured Assessment for the Genetics of Alcoholism. 150 control subjects without psychiatric disorders were also recruited. The control group was ethnically-, age- and gender-matched to the patients. The DRD2 TaqIA, exon 8, and promoter -141C ins/del polymorphisms as well as COMT Val158Met, 5HTT 44 bp del in promoter, and DAT 40 bp VNTR polymorphisms were detected by means of PCR. No significant differences were observed when the whole group of alcoholics and the controls were compared. Similarly, there were no differences between either the Lesch type I or type II alcoholics and the control subjects. No significant differences were observed between type I and type II alcoholics. Alleles frequencies were not calculated for the Lesch type III and type IV alcoholics since the number of patients was too small. The present results argue against any major role of the investigated polymorphisms in either Lesch type I or type II alcoholism. More comprehensive studies are needed to define the role of the investigated polymorphisms in Lesch type III and type IV alcoholism.
Grandin, Nathalie; Charbonneau, Michel
2007-01-01
Saccharomyces cerevisiae telomerase-negative cells undergo homologous recombination on subtelomeric or TG1–3 telomeric sequences, thus allowing Type I or Type II post-senescence survival, respectively. Here, we find that the DNA damage sensors, Mec1, Mec3 and Rad24 control Type II recombination, while the Rad9 adaptor protein and the Rad53 and Chk1 effector kinases have no effect on survivor type selection. Therefore, the Mec1 and Mec3 checkpoint complexes control telomeric recombination independently of their roles in generating and amplifying the Mec1-Rad53-Chk1 kinase cascade. rfa1-t11 mutant cells, bearing a mutation in Replication Protein A (RPA) conferring a defect in recruiting Mec1-Ddc2, were also deficient in both types of telomeric recombination. Importantly, expression of an Rfa1-t11-Ddc2 hybrid fusion protein restored checkpoint-dependent arrest, but did not rescue defective telomeric recombination. Therefore, the Rfa1-t11-associated defect in telomeric recombination is not solely due to its failure to recruit Mec1. We have also isolated novel alleles of RFA1 that were deficient in Type I but not in Type II recombination and proficient in checkpoint control. Therefore, the checkpoint and recombination functions of RPA can be genetically separated, as can the RPA-mediated control of the two types of telomeric recombination. PMID:17202155
Yoshimasu, K
2001-01-01
To study the relation of type A behavior pattern and job-related psychosocial factors to the risk of myocardial infarction. Study subjects comprised 290 cases (173 male workers and 117 women) of nonfatal acute myocardial infarction (AMI) and 489 controls (303 male workers and 186 women) recruited from among residents of the study area. Participation rates of cases and controls were 86% and 50%, respectively. Type A behavior pattern, job-related psychosocial factors, and other coronary risk factors were ascertained by interview using a questionnaire. Type A behavior pattern was measured by 12 questions, and job strain by the method of Karasek. Logistic regression analysis was used to calculate odds ratio and 95% confidence interval with adjustment for potential confounding variables. The relation to job strain was examined only in men. Type A behavior pattern was significantly associated with an increased risk of AMI in male workers (adjusted OR = 1.9, 95% CI, 1.2-2.9) and in women (adjusted OR = 2.8, 95% CI, 1.6-4.9). Although job control and job demand showed no material association with AMI, job strain, a combination of low job control and high job demand was associated with an increased risk of AMI (adjusted OR = 2.2, 95% CI, 1.1-4.5). Abbreviated type A score and job demand score were higher among nonparticipant control candidates than participant controls in male workers. Type A behavior pattern may be an important risk factor for AMI especially in Japanese women. The present study also revealed persons in stressful psychosocial circumstances were less likely to participate in the study.
Serum leptin and its relationship with metabolic variables in Arabs with type 2 diabetes mellitus.
Al-Shoumer, Kamal A; Al-Asousi, Adnan A; Doi, Suhail A; Vasanthy, Bagavathy A
2008-01-01
Most studies on serum leptin in type 2 diabetes mellitus have focused on white populations. We studied serum leptin concentrations and parameters related to glycemic control and the association between leptin levels and anthropometric and metabolic factors in Arab patients with type 2 diabetes and in Arab control subjects. Ninety-two patients (65 females and 27 males) with type 2 diabetes and 69 matched normal control subjects (48 females and 21 males) were included. Anthropometric measures (including body mass index [BMI] and waist:hip ratio) were assessed in all subjects. After an overnight fast, blood was collected for serum leptin assay. Other metabolic parameters including glucose, insulin, C-peptide, intact proinsulin, insulin resistance index (HOMA-IR), insulin-like growth factor 1 (IGF-1), lipids and hemoglobin A1c (HbA1c) were determined. Fasting serum leptin levels, IGF-1 and high-density lipoprotein (HDL) cholesterol were similar in patients with type 2 diabetes and control subjects. When obese subjects (BMI > or =30 kg/m2) were analyzed separately, serum levels of leptin were significantly lower in patients compared to controls. In contrast, patients had higher fasting glucose, insulin, C-peptide, intact proinsulin, insulin resistance, total cholesterol, triglycerides, HbA1c, and a larger waist circumference and waist-to-hip ratio than controls. Serum leptin correlated positively with BMI, negatively with waist-to-hip ratio, and demonstrated no relationship to other parameters. Patients with type 2 diabetes in an Arab ethnic population showed evidence of an unfavorable metabolic profile despite having leptin levels similar to controls. Obesity influences serum leptin levels more significantly in type 2 diabetes, in which leptin levels tends to be low.
Iannacone, Michelle R; Gheit, Tarik; Pfister, Herbert; Giuliano, Anna R; Messina, Jane L; Fenske, Neil A; Cherpelis, Basil S; Sondak, Vernon K; Roetzheim, Richard G; Silling, Steffi; Pawlita, Michael; Tommasino, Massimo; Rollison, Dana E
2014-05-01
Cutaneous human papillomaviruses (HPV) have been reported in cutaneous squamous cell carcinoma (SCC). We conducted a clinic-based case-control study to investigate the association between genus-beta HPV DNA in eyebrow hairs (EBH) and SCC. EBH from 168 SCC cases and 290 controls were genotyped for genus-beta HPV DNA. SCC tumors from a subset of cases (n = 142) were also genotyped. Viral load was determined in a subset of specimens positive for a single HPV type. Associations with SCC were estimated by odds ratios (OR) and 95% confidence intervals (CI) adjusted for age and sex using logistic regression. Statistical tests were two-sided. EBH DNA prevalence was greater in cases (87%) than controls (73%) (p < 0.05), and the association with SCC increased with the number of HPV types present, (≥ 4 types vs. HPV-negative: OR = 2.02, 95% CI = 1.07-3.80; p(trend) = 0.02). Type-specific associations were observed between SCC and DNA in EBH for HPV23 (OR = 1.90, 95% CI = 1.10-3.30) and HPV38 (OR = 1.84, 95% CI = 1.04-3.24). Additionally, when compared with the controls, the DNA prevalence in EBH was significantly higher among cases for 11 of the 25 genus-beta types tested, when accounting for DNA for the same HPV type in the tumor (ORs = 3.44-76.50). Compared to controls, the mean viral DNA load in EBH among the selected cases was greater for HPV5, HPV8 and HPV24, but lower for HPV38. SCC cases were more likely than controls to have HPV DNA+ EBH for single and multiple HPV types, providing additional support for the potential role of genus-beta HPV infections in SCC development. © 2013 UICC.
Krul-Poel, Yvonne H M; van Wijland, Hans; Stam, Frank; ten Boekel, Edwin; Lips, Paul; Simsek, Suat
2014-07-17
Besides the classical role of vitamin D on calcium and bone homeostasis, vitamin D deficiency has recently been identified as a contributing factor in the onset of insulin resistance in type 2 diabetes mellitus. However, it is uncertain whether vitamin D deficiency and poor glycaemic control are causally interrelated or that they constitute two independent features of type 2 diabetes mellitus. There are limited clinical trials carried out which measured the effect of vitamin D supplementation on glycaemic control.The objective of this study is to investigate the effect of vitamin D supplementation on glycaemic control and quality of life in patients with type 2 diabetes mellitus. In a randomised double-blind placebo-controlled trial conducted in five general practices in the Netherlands three hundred patients with type 2 diabetes mellitus treated with lifestyle advises or metformin or sulphonylurea-derivatives are randomised to receive either placebo or 50,000 IU Vitamin D3 at monthly intervals. The primary outcome measure is the change in glycated haemoglobin level between baseline and six months. Secondary outcome measures include blood pressure, anthropometric parameters, lipid profile, insulin resistance, quality of life, advanced glycation end products and safety profiles. Quality of life will be measured by The Short Form (SF-36) Health Survey questionnaire. Advanced glycation end products are measured by an AGE-reader. This trial will be the first study exploring the effect of vitamin D supplementation on both glycaemic control and quality of life in patients with type 2 diabetes mellitus. Our findings will contribute to the knowledge of the relationship between vitamin D status and insulin resistance in patients with type 2 diabetes mellitus. The Netherlands trial register: NTR3154.
Cushing's syndrome in type 2 diabetes patients with poor glycemic control.
Gungunes, Askin; Sahin, Mustafa; Demirci, Taner; Ucan, Bekir; Cakir, Evrim; Arslan, Muyesser Sayki; Unsal, Ilknur Ozturk; Karbek, Basak; Calıskan, Mustafa; Ozbek, Mustafa; Cakal, Erman; Delibasi, Tuncay
2014-12-01
Cushing's syndrome may be more frequent in some specific patient groups such as type 2 diabetes and obesity. The aim of this study was to investigate the prevalence of Cushing's syndrome in outpatients with type 2 diabetes with poor glycemic control despite at least 3-months insulin therapy. Outpatients with type 2 diabetes whose glycemic control is poor (Hb Alc value >7 %) despite receiving at least 3-months long insulin treatment (insulin alone or insulin with oral antidiabetics) were included. Patients with classic features of Cushing's syndrome were excluded. Overnight 1 mg dexamethasone suppression test (DST) was performed as a screening test. A total of 277 patients with type 2 diabetes whose glycemic control is poor (Hb Alc value >7 %) despite insulin therapy were included. Two of the 277 patients with type 2 diabetes were diagnosed with Cushing's syndrome (0.72 %). Hypertension was statistically more frequent in the patients with cortisol levels ≥1.8 μg/dL than the patients with cortisol levels <1.8 μg/dL after overnight 1 mg DST (p = 0.041). Statistically significant correlation was determined between cortisol levels after 1 mg DST and age, daily insulin dose (r = 0.266 and p < 0.001, r = 0.163 and p = 0.008, respectively). According to our findings, the prevalence of Cushing's syndrome among patients with type 2 diabetes with poor glycemic control despite insulin therapy is much higher than in the general population. The patients with type 2 diabetes with poor glycemic control despite at least three months of insulin therapy should be additionally tested for Cushing's syndrome if they have high dose insülin requirements.
Kurien, M; Leeds, J S; Hopper, A D; Wild, G; Egner, W; Tesfaye, S; Hadjivassiliou, M; Sanders, D S
2013-07-01
Immunoglobulin A (IgA) measurement is advocated when case finding for coeliac disease in patients with Type 1 diabetes mellitus. Currently, there is a paucity of contemporary studies assessing IgA deficiency in Type 1 diabetes. This study evaluates the prevalence of IgA deficiency in individuals with Type 1 diabetes, compared with patients with coeliac disease and control subjects. In addition, we evaluate whether routine IgA measurement is justifiable when case finding for coeliac disease in patients with Type 1 diabetes. All patients were assessed using IgA endomysial antibodies, IgA anti-tissue transglutaminase antibodies and total IgA levels. Altogether, 2434 individuals were tested: 1000 patients with Type 1 diabetes, 234 patients with coeliac disease and 1200 population control subjects. Definitive IgA deficiency was defined as total IgA levels < 0.07 g/l. The prevalence of IgA deficiency was significantly more common in patients with Type 1 diabetes (0.9%, n = 9/1000; P = 0.036) and coeliac disease (1.29%, n = 3/234; P = 0.041) when compared with population control subjects (prevalence of 0.17%, 2/1200). No statistical difference between Type 1 diabetes and coeliac disease for IgA deficiency was identified (P = 0.87). Of patients in the group with Type 1 diabetes, 3.3% (33/1000) had coeliac disease, and of those only one patient had IgA deficiency leading to an antibody-negative presentation. Both IgA-deficient individuals within the population control subjects had normal duodenal biopsies and no relevant symptoms. IgA deficiency is more common in Type 1 diabetes compared with population control subjects. Despite this, very few individuals with Type 1 diabetes and IgA deficiency appear to have villous atrophy on biopsy. These outcomes question the practice of routine IgA measurement when case finding for coeliac disease in patients with Type 1 diabetes. © 2013 The Authors. Diabetic Medicine © 2013 Diabetes UK.
NASA Technical Reports Server (NTRS)
Vasu, George; Pack, George J
1951-01-01
Correlation has been established between transient engine and control data obtained experimentally and data obtained by simulating the engine and control with an analog computer. This correlation was established at sea-level conditions for a turbine-propeller engine with a relay-type speed control. The behavior of the controlled engine at altitudes of 20,000 and 35,000 feet was determined with an analog computer using the altitude pressure and temperature generalization factors to calculate the new engine constants for these altitudes. Because the engine response varies considerably at altitude some type of compensation appears desirable and four methods of compensation are discussed.
Bian, Zhao-Xiang; Moher, David; Dagenais, Simon; Li, You-Ping; Liu, Liang; Wu, Tai-Xiang; Miao, Jiang-Xia
2006-03-01
To discuss the types of control groups in randomized controlled trials (RCTs) of Chinese herbal medicine (CHM), and to provide suggestions for improving the design of control group in future clinical studies in this therapeutic area. A search of the Cochrane Library was conducted in July 2005 to identify RCTs of CHM, and 66 RCTs with CHM for type 2 diabetes mellitus were obtained as the basis for further analysis. Of 66 RCTs with CHM for type 2 diabetes mellitus, 61 (92.4%) trials had both a treatment group and a control group. Twenty-seven (40.9%) RCTs compared CHM plus conventional drug vs conventional drug, 24 (36.4%) compared CHM vs conventional drug, 5 (7.6%) compared CHM vs placebo, 3 (4.5%) compared CHM plus conventional drug vs conventional drug plus placebo, 3 (4.5%) compared CHM plus conventional drug vs other CHM, 1 (1.5%) compared CHM vs no treatment, 1 (1.5%) compared CHM plus placebo vs conventional drug plus placebo, 1 (1.5%) compared CHM vs CHM plus conventional drug vs conventional drug vs placebo, and 1 (1.5%) compared CHM vs conventional drug vs CHM plus conventional drug. A variety of control groups were used in RCTs of CHM for type 2 diabetes mellitus, including placebo, active, and no treatment control groups. Justification for selecting particular types of control groups were not provided in the trials reviewed in this study. Different control groups may be appropriate according to the study objectives, and several factors should be considered prior to selecting control groups in future RCTs of CHM. (1) Investigators of CHM who design clinical trials should understand the rationale for selecting different types of control groups; (2) Control groups for RCTs should be selected according to study objectives; (3) Active control groups should select interventions for comparisons that have the strongest evidence of efficacy and prescribe them as recommended; (4) Placebo control groups should select a placebo that mimics the physical characteristics of test intervention as closely as possible and is completely inert; (5) No treatment control groups should only be used when withholding treatment is ethical and objectives outcomes will not be subject to bias due to absent blinding; (6) Crossover control groups may be appropriate in chronic and stable conditions.
Effect of controlled exercise on middle gluteal muscle fibre composition in Thoroughbred foals.
Eto, D; Yamano, S; Kasashima, Y; Sugiura, T; Nasu, T; Tokuriki, M; Miyata, H
2003-11-01
Most racehorses are trained regularly from about age 18 months; therefore, little information is available on the effect of training in Thoroughbred foals. Well-controlled exercise could improve muscle potential ability for endurance running. Thoroughbred foals at age 2 months were separated into control and training (treadmill exercise) groups and samples obtained from the middle gluteal muscle at 2 and 12 months post partum. Muscle fibre compositions were determined by histochemical and electrophoretical techniques and succinic dehydrogenase (SDH) activity was analysed in each fibre type. All fibre types were hypertrophied with growth and type I and IIA fibres were significantly larger in the training than the control group at age 12 months. A significant increase of SDH activity was found in type IIX muscle fibres in the training group. Training in young Thoroughbred horses can facilitate muscle fibre hypertrophy and increase the oxidative capacity of type IIX fibres, which could potentially enhance stamina at high speeds. To apply this result to practical training, further studies are needed to determine more effective and safe intensities of controlled exercise.
SERUM magnesium levels as an indicator of status of Diabetes Mellitus type 2.
Ramadass, S; Basu, Sharbari; Srinivasan, A R
2015-01-01
Magnesium deficiency is commonly associated with endocrine and metabolic disorders, especially with Diabetes Mellitus type 2 though the mechanism of hypomagnesemia in Diabetes Mellitus is not completely known. There is a close association between metabolic control of Diabetes Mellitus and impaired magnesium balance. To estimate the serum levels of magnesium in patients of with Diabetes Mellitus type 2 and to find a correlation if any, with the duration and control (by estimating HbA1c) of Diabetes Mellitus type 2. Fifty patients of Diabetes Mellitus type 2 were included in the study. Blood samples were analyzed for fasting and post prandial glucose, HbA1c and magnesium. The patients were grouped into three categories based upon their HbA1c levels into those with good control, need intervention and poor control. The three groups were compared with reference to their mean levels of blood glucose and magnesium. Association of serum magnesium levels with HbA1c, Fasting and postprandial blood glucose and duration of Diabetes Mellitus was also done. Serum magnesium levels were found to decline with rise in HbA1c levels and with duration of Diabetes Mellitus type 2. Hypomagnesemia is linked to poor control of Diabetes Mellitus type 2 and depletion of serum magnesium occurs exponentially with duration of disease. Copyright © 2014 Diabetes India. Published by Elsevier Ltd. All rights reserved.
Ultimate boundedness stability and controllability of hereditary systems
NASA Technical Reports Server (NTRS)
Chukwu, E. N.
1979-01-01
By generalizing the Liapunov-Yoshizawa techniques, necessary and sufficient conditions are given for uniform boundedness and uniform ultimate boundedness of a rather general class of nonlinear differential equations of neutral type. Among the applications treated by the methods are the Lienard equation of neutral type and hereditary systems of Lurie type. The absolute stability of this later equation is also investigated. A certain existence result of a solution of a neutral functional differential inclusion with two point boundary values is applied to study the exact function space controllability of a nonlinear neutral functional differential control system. A geometric growth condition is used to characterize both the function space and Euclidean controllability of another nonlinear delay system which has a compact and convex control set. This yields conditions under which perturbed nonlinear delay controllable systems are controllable.
Central Regulation of Glucose Production May Be Impaired in Type 2 Diabetes
Esterson, Yonah B.; Carey, Michelle; Boucai, Laura; Goyal, Akankasha; Raghavan, Pooja; Zhang, Kehao; Mehta, Deeksha; Feng, Daorong; Wu, Licheng; Kehlenbrink, Sylvia; Koppaka, Sudha; Kishore, Preeti
2016-01-01
The challenges of achieving optimal glycemic control in type 2 diabetes highlight the need for new therapies. Inappropriately elevated endogenous glucose production (EGP) is the main source of hyperglycemia in type 2 diabetes. Because activation of central ATP-sensitive potassium (KATP) channels suppresses EGP in nondiabetic rodents and humans, this study examined whether type 2 diabetic humans and rodents retain central regulation of EGP. The KATP channel activator diazoxide was administered in a randomized, placebo-controlled crossover design to eight type 2 diabetic subjects and seven age- and BMI-matched healthy control subjects. Comprehensive measures of glucose turnover and insulin sensitivity were performed during euglycemic pancreatic clamp studies following diazoxide and placebo administration. Complementary rodent clamp studies were performed in Zucker Diabetic Fatty rats. In type 2 diabetic subjects, extrapancreatic KATP channel activation with diazoxide under fixed hormonal conditions failed to suppress EGP, whereas matched control subjects demonstrated a 27% reduction in EGP (P = 0.002) with diazoxide. Diazoxide also failed to suppress EGP in diabetic rats. These results suggest that suppression of EGP by central KATP channel activation may be lost in type 2 diabetes. Restoration of central regulation of glucose metabolism could be a promising therapeutic target to reduce hyperglycemia in type 2 diabetes. PMID:27207526
Nakamura, H; Iwamoto, M; Ogata, T; Washida, K; Sekine, K; Takase, M; Park, B J; Morikawa, T; Miyazaki, Y
2008-01-01
This study examined the influence of milk casein-derived peptides on cerebral activity after mental stress loading. In a crossover study, 16 male students were given a drink containing peptides (peptide group), or water (control group) before stress loading. The oxyhaemoglobin (HbO(2)) concentration in the prefrontal area of the brain and work efficiency were measured as indicators of cerebral activity and differences in these parameters were examined according to type A or type B personality. Type A behaviour was defined as: aggression-hostility, hard-driving-time-urgency and speed-power, whereas type B behaviour did not have these characteristics. Peptide intake resulted in a significant increase in both HbO(2) concentration and work efficiency, whilst a similar increase was not seen in the control group. When divided into type A or type B personality, the changes in HbO(2) concentration for the control group differed significantly in the right prefrontal area. Moreover, in type A subjects the HbO(2) concentration in the right prefrontal area following intake was significantly different between the peptide and control groups.
Zeghlache, Samir; Benslimane, Tarak; Bouguerra, Abderrahmen
2017-11-01
In this paper, a robust controller for a three degree of freedom (3 DOF) helicopter control is proposed in presence of actuator and sensor faults. For this purpose, Interval type-2 fuzzy logic control approach (IT2FLC) and sliding mode control (SMC) technique are used to design a controller, named active fault tolerant interval type-2 Fuzzy Sliding mode controller (AFTIT2FSMC) based on non-linear adaptive observer to estimate and detect the system faults for each subsystem of the 3-DOF helicopter. The proposed control scheme allows avoiding difficult modeling, attenuating the chattering effect of the SMC, reducing the rules number of the fuzzy controller. Exponential stability of the closed loop is guaranteed by using the Lyapunov method. The simulation results show that the AFTIT2FSMC can greatly alleviate the chattering effect, providing good tracking performance, even in presence of actuator and sensor faults. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.
ERIC Educational Resources Information Center
Semrud-Clikeman, Margaret; Walkowiak, Jenifer; Wilkinson, Alison; Butcher, Brianne
2010-01-01
The purpose of the study was to evaluate neuropsychological and behavioral rating measures of executive functions (EF) in children with two subtypes of ADHD, Asperger syndrome (AS), and controls. Relative to the control group, the clinical groups experienced more difficulty in EF. The AS group showed the most difficulty in emotional control,…
Relationship between vitamin D and glycemic control in patients with type 2 diabetes mellitus.
Olt, Serdar
2015-01-01
Herein I investigated the impact of vitamin D on glycemic control in patients with type 2 diabetes mellitus. 128 patients with type 2 diabetes mellitus were enrolled in this study (mean (S.D) age: 57.7±10 years, 26.6% were female). It was collected clinical and laboratory characteristics of patients from hospital records retrospectively. Patients were divided into two groups according to the HBA1c values: good glycemic control (HbA1c≤7%) and poor glycemic control (HbA1c>7%). It was compared 25 hydroxyvitamin (OH) D and other collected laboratory parameters between the two groups. The vitamin D deficiency rate was 98.3%. In the result with ROC curve analyzes and Mann Whitney U test vitamin D was'nt significantly associated with glycemic control (P value >0.05). Among other parameters result with ROC curve analyzes and student t test RDW-CV was found to be significantly associated with glycemic control (P value <0.05). Although high level of vitamin D deficiency, present study indicated that vitamin D was'nt significantly related to glycemic control in type 2 diyabetes mellitus. Even so RDW-CV was significantly related to glycemic control.
Relationship between vitamin D and glycemic control in patients with type 2 diabetes mellitus
Olt, Serdar
2015-01-01
Herein I investigated the impact of vitamin D on glycemic control in patients with type 2 diabetes mellitus. 128 patients with type 2 diabetes mellitus were enrolled in this study (mean (S.D) age: 57.7±10 years, 26.6% were female). It was collected clinical and laboratory characteristics of patients from hospital records retrospectively. Patients were divided into two groups according to the HBA1c values: good glycemic control (HbA1c≤7%) and poor glycemic control (HbA1c>7%). It was compared 25 hydroxyvitamin (OH) D and other collected laboratory parameters between the two groups. The vitamin D deficiency rate was 98.3%. In the result with ROC curve analyzes and Mann Whitney U test vitamin D was’nt significantly associated with glycemic control (P value >0.05). Among other parameters result with ROC curve analyzes and student t test RDW-CV was found to be significantly associated with glycemic control (P value <0.05). Although high level of vitamin D deficiency, present study indicated that vitamin D was’nt significantly related to glycemic control in type 2 diyabetes mellitus. Even so RDW-CV was significantly related to glycemic control. PMID:26770553
Optimizing the Primary Prevention of Type-2 Diabetes in Primary Health Care
2017-08-18
Interprofessional Relations; Primary Health Care/Organization & Administration; Diabetes Mellitus, Type 2/Prevention & Control; Primary Prevention/Methods; Risk Reduction Behavior; Randomized Controlled Trial; Life Style
Merzouk, H; Bouchenak, M; Loukidi, B; Madani, S; Prost, J; Belleville, J
2000-01-01
Aims—To determine the effects of fetal macrosomia related to maternal type 1 diabetes on the lipid transport system. Methods—Serum lipoprotein concentrations and composition and lecithin:cholesterol acyltransferase (LCAT) activity were investigated in macrosomic newborns (mean birth weight, 4650 g; SEM, 90) and their mothers with poorly controlled type 1 diabetes, in appropriate for gestational age newborns (mean birth weight, 3616 g; SEM, 68) and their mothers with well controlled type 1 diabetes, and macrosomic (mean birth weight, 4555 g; SEM, 86) or appropriate for gestational age (mean birth weight, 3290 g; SEM, 45) newborns and their healthy mothers. Results—In mothers with well controlled type 1 diabetes, serum lipids, apolipoproteins, and lipoproteins were comparable with those of healthy mothers. Similarly, in their infants, these parameters did not differ from those of appropriate for gestational age newborns. Serum triglyceride, very low density lipoprotein (VLDL), apolipoprotein B100 (apo B100), and high density lipoprotein (HDL) triglyceride concentrations were higher, whereas serum apo A-I and HDL3 concentrations were lower in mothers with diabetes and poor glycaemic control than in healthy mothers. Their macrosomic newborns had higher concentrations in all serum lipids and lipoproteins, with high apo A-I and apo B100 values compared with appropriate for gestational age newborns. In macrosomic infants of healthy mothers, there were no significant differences in lipoprotein profiles compared with those of appropriate for gestational age infants. LCAT activity was similar in both groups of mothers and newborns. Conclusion—Poorly controlled maternal type 1 diabetes and fetal macrosomia were associated with lipoprotein abnormalities. Macrosomic lipoprotein profiles related to poor metabolic control of type 1 diabetes appear to have implications for later metabolic diseases. Key Words: apolipoproteins • lipids • lipoproteins • lecithin:cholesterol acyltransferase • fetal macrosomia • maternal type 1 diabetes PMID:11265176
Knorr, Sine; Clausen, Tine D; Vlachová, Zuzana; Bytoft, Birgitte; Damm, Peter; Beck-Nielsen, Henning; Jensen, Dorte M; Juul, Svend; Gravholt, Claus Højbjerg
2015-07-01
This study examined the effect of maternal pregestational type 1 diabetes on offspring primary school performance. We performed a prospective combined clinical and register-based cohort study comparing primary school performance in offspring (n = 707) of women with pregestational type 1 diabetes with matched control offspring (n = 60,341). We also examined the association between HbA1c levels during pregnancy and later school performance among offspring born to women with pregestational type 1 diabetes. Offspring of mothers with pregestational type 1 diabetes obtained similar school grades as control offspring when finishing primary school (regression coefficient [β] = -0.13; 95% CI = -0.30 to 0.03; P = 0.12). Adjusting for parental education also resulted in an insignificant difference between the two groups (β = -0.07; 95% CI = -0.23 to 0.09; P = 0.37). Among offspring of women with type 1 diabetes, increasing maternal HbA1c pregestationally and throughout the pregnancy was associated with lower average school grades. Offspring born to mothers with good glycemic control in the third trimester obtained higher average school grades compared with control offspring. The opposite applied to offspring born to mothers with inadequate glycemic control, who obtained significantly lower average school grades compared with control offspring. Offspring of mothers with pregestational type 1 diabetes obtained similar average grades when finishing primary school compared with matched control offspring. Among offspring of women with type 1 diabetes, we found a consistent negative association between maternal HbA1c in pregnancy and primary school grades. However, whether this association reflects a direct causal influence of intrauterine hyperglycemia is uncertain. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.
30 CFR 250.502 - Equipment movement.
Code of Federal Regulations, 2013 CFR
2013-07-01
... District Manager. A closed surface-controlled subsurface safety valve of the pump-through type may be used in lieu of the pump-through-type tubing plug, provided that the surface control has been locked out... be shut in below the surface with a pump-through-type tubing plug and at the surface with a closed...
30 CFR 250.602 - Equipment movement.
Code of Federal Regulations, 2011 CFR
2011-07-01
... otherwise approved by the District Manager. A closed surface-controlled subsurface safety valve of the pump-through-type may be used in lieu of the pump-through-type tubing plug provided that the surface control... producing hydrocarbons shall be shut in below the surface with a pump-through-type tubing plug and at the...
30 CFR 250.602 - Equipment movement.
Code of Federal Regulations, 2012 CFR
2012-07-01
... District Manager. A closed surface-controlled subsurface safety valve of the pump-through-type may be used in lieu of the pump-through-type tubing plug provided that the surface control has been locked out of... be shut in below the surface with a pump-through-type tubing plug and at the surface with a closed...
30 CFR 250.602 - Equipment movement.
Code of Federal Regulations, 2013 CFR
2013-07-01
... District Manager. A closed surface-controlled subsurface safety valve of the pump-through-type may be used in lieu of the pump-through-type tubing plug provided that the surface control has been locked out of... be shut in below the surface with a pump-through-type tubing plug and at the surface with a closed...
30 CFR 250.502 - Equipment movement.
Code of Federal Regulations, 2014 CFR
2014-07-01
... District Manager. A closed surface-controlled subsurface safety valve of the pump-through type may be used in lieu of the pump-through-type tubing plug, provided that the surface control has been locked out... be shut in below the surface with a pump-through-type tubing plug and at the surface with a closed...
30 CFR 250.502 - Equipment movement.
Code of Federal Regulations, 2011 CFR
2011-07-01
... otherwise approved by the District Manager. A closed surface-controlled subsurface safety valve of the pump-through type may be used in lieu of the pump-through-type tubing plug, provided that the surface control... producing hydrocarbons shall be shut in below the surface with a pump-through-type tubing plug and at the...
30 CFR 250.602 - Equipment movement.
Code of Federal Regulations, 2014 CFR
2014-07-01
... District Manager. A closed surface-controlled subsurface safety valve of the pump-through-type may be used in lieu of the pump-through-type tubing plug provided that the surface control has been locked out of... be shut in below the surface with a pump-through-type tubing plug and at the surface with a closed...
30 CFR 250.502 - Equipment movement.
Code of Federal Regulations, 2012 CFR
2012-07-01
... District Manager. A closed surface-controlled subsurface safety valve of the pump-through type may be used in lieu of the pump-through-type tubing plug, provided that the surface control has been locked out... be shut in below the surface with a pump-through-type tubing plug and at the surface with a closed...
Increased ability of LDL from normolipidemic type 2 diabetic women to generate peroxides.
Guerci, B; Antebi, H; Meyer, L; Durlach, V; Ziegler, O; Nicolas, J P; Alcindor, L G; Drouin, P
1999-09-01
We assessed the ability of LDL from 30 type 1 diabetic patients (18 men, 12 women), 65 type 2 diabetic patients (35 men, 30 women), and 35 controls (19 men, 16 women) to generate peroxides. The men and women in the diabetic groups were studied separately and matched for age, body mass index, duration of diabetes, glycohemoglobin, and conventional lipid characteristics according to the presence or absence of hyperlipidemia. The ability of LDL to form peroxides was assessed by measuring the thiobarbituric acid-reactive substances corrected for LDL-cholesterol [ratio of malondialdehyde (MDA) to LDL-cholesterol]. LDL particle size was expressed as the ratio of LDL-cholesterol to apolipoprotein B (LDL-cholesterol/apoB). The MDA/LDL-cholesterol ratio was higher in type 1 and type 2 diabetic patients with hyperlipidemia than in controls. The MDA/LDL-cholesterol ratio was also higher in type 2 normolipidemic women than in controls (P <0.01). The LDL-cholesterol/apoB ratio was lower in type 2 diabetic women than in type 2 diabetic men (P <0.05). The MDA/LDL-cholesterol ratio was negatively correlated with the LDL-cholesterol/apoB ratio (r = -0.78, P <0.001) in hyperlipidemic type 1 (not type 2) diabetic patients. In normolipidemic type 2 diabetic patients, the MDA/LDL-cholesterol ratio was also negatively correlated with the LDL-cholesterol/apoB ratio (r = -0.75, P <0.001) because of the highly significant negative correlation in type 2 diabetic women (r = -0.89, P <0.01). LDL from well-controlled type 2 diabetic women is smaller and more prone to form peroxides. This could explain why diabetic women are at greater risk of cardiovascular disease.
Regnell, Simon E; Peterson, Pernilla; Trinh, Lena; Broberg, Per; Leander, Peter; Lernmark, Åke; Månsson, Sven; Elding Larsson, Helena
2015-08-01
Children with type 1 diabetes have been identified as a risk group for non-alcoholic fatty liver disease (NAFLD). The aim was to compare total hepatic fat fraction and fat distribution across Couinaud segments in children with type 1 diabetes and controls and the relation of hepatic fat to plasma and anthropometric parameters. Hepatic fat fraction and fat distribution across Couinaud segments were measured with magnetic resonance imaging (MRI) in 22 children with type 1 diabetes and 32 controls. Blood tests and anthropometric data were collected. No children had NAFLD. Children with type 1 diabetes had a slightly lower hepatic fat fraction (median 1.3%) than controls (median 1.8%), and their fat had a different segmental distribution. The fat fraction of segment V was the most representative of the liver as a whole. An incidental finding was that diabetes patients treated with multiple daily injections of insulin (MDI) had a fat distribution more similar to controls than patients with continuous subcutaneous insulin infusion (CSII). In children with type 1 diabetes, NAFLD may be less common than recent studies have suggested. Children with type 1 diabetes may have a lower fat fraction and a different fat distribution in the liver than controls. Diabetes treatment with MDI or CSII may affect liver fat, but this needs to be confirmed in a larger sample of patients. The heterogeneity of hepatic fat infiltration may affect results when liver biopsy is used for diagnosing fatty liver. Copyright © 2015 Elsevier Inc. All rights reserved.
Reynolds, D Brice; Walker, Rebekah J; Campbell, Jennifer A; Egede, Leonard E
2015-04-01
Discrimination has been linked to negative health outcomes, but little research has investigated different types of discrimination to determine if some have a greater impact on outcomes. We examined the differential effect of discrimination based on race, level of education, gender, and language on glycemic control in adults with type 2 diabetes. Six hundred two patients with type 2 diabetes from two adult primary care clinics in the southeastern United States completed validated questionnaires. Questions included perceived discrimination because of race/ethnicity, level of education, sex/gender, or language. A multiple linear regression model assessed the differential effect of each type of perceived discrimination on glycemic control while adjusting for relevant covariates, including race, site, gender, marital status, duration of diabetes, number of years in school, number of hours worked per week, income, and health status. The mean age was 61.5 years, and the mean duration of diabetes was 12.3 years. Of the sample, 61.6% were men, and 64.9% were non-Hispanic black. In adjusted models, education discrimination remained significantly associated with glycemic control (β=0.47; 95% confidence interval, 0.03, 0.92). Race, gender and language discrimination were not significantly associated with poor glycemic control in either unadjusted or adjusted analyses. Discrimination based on education was found to be significantly associated with poor glycemic control. The findings suggest that education discrimination may be an important social determinant to consider when providing care to patients with type 2 diabetes and should be assessed separate from other types of discrimination, such as that based on race.
An Internal Data Non-hiding Type Real-time Kernel and its Application to the Mechatronics Controller
NASA Astrophysics Data System (ADS)
Yoshida, Toshio
For the mechatronics equipment controller that controls robots and machine tools, high-speed motion control processing is essential. The software system of the controller like other embedded systems is composed of three layers software such as real-time kernel layer, middleware layer, and application software layer on the dedicated hardware. The application layer in the top layer is composed of many numbers of tasks, and application function of the system is realized by the cooperation between these tasks. In this paper we propose an internal data non-hiding type real-time kernel in which customizing the task control is possible only by change in the program code of the task side without any changes in the program code of real-time kernel. It is necessary to reduce the overhead caused by the real-time kernel task control for the speed-up of the motion control of the mechatronics equipment. For this, customizing the task control function is needed. We developed internal data non-cryptic type real-time kernel ZRK to evaluate this method, and applied to the control of the multi system automatic lathe. The effect of the speed-up of the task cooperation processing was able to be confirmed by combined task control processing on the task side program code using an internal data non-hiding type real-time kernel ZRK.
Participant Characteristics and the Effects of Two Types of Meditation versus Quiet Sitting.
ERIC Educational Resources Information Center
Fling, Sheila; And Others
1981-01-01
Compared restricted and expanded awareness types of meditation with quiet sitting, and controls. All groups except controls became less anxious, more intuitive, and more internal on locus of control. Found little evidence of differential change across groups. Those practicing more showed more anxiety reduction. (JAC)
Mean Field Type Control with Congestion
DOE Office of Scientific and Technical Information (OSTI.GOV)
Achdou, Yves, E-mail: achdou@ljll.univ-paris-diderot.fr; Laurière, Mathieu
2016-06-15
We analyze some systems of partial differential equations arising in the theory of mean field type control with congestion effects. We look for weak solutions. Our main result is the existence and uniqueness of suitably defined weak solutions, which are characterized as the optima of two optimal control problems in duality.
Klein, Tracy A; Panther, Shannon; Woo, Teri; Odom-Maryon, Tamara; Daratha, Kenn
2016-08-01
This study compares nurse practitioner (NP) and physician (MD/DO) prescribing patterns for treatment of children with an attention-deficit/hyperactivity disorder (ADHD)-related diagnosis covered by Oregon Medicaid from 2012 to 2013. This study is a limited data set review of Oregon pharmacy claims for youth aged 3-18 at time of prescription fill, who were continuously enrolled for at least 10 months of the index year. Claims with selected ICD-9 codes (n = 197,364) were further defined by 30-day prescriptions and prescription drug events (PDE) linked to each prescriber type of interest. Descriptive statistical analysis of variables included prescriber type (NP vs. physician) and specialty (generalist vs. specialist), child age, and controlled versus noncontrolled drug type. A total of 82,754 complete 30-day prescriptions for 10,753 children from 1785 unique prescribers (78 NP specialists; 303 NP generalists; 162 physician specialists; and 1242 physician generalist prescribers) and 16,669 PDE were analyzed. Physicians prescribed more than 81% of all ADHD medications, and physician generalists prescribed nearly 60% of all prescriptions. Sixty-four percent of 30-day supply prescriptions (n = 52,678) were controlled substances. Generalists, both NPs and physician prescribers, prescribed controlled medications more often than specialists. Physician specialists consistently prescribed controlled substances for all age groups, while NP specialists prescribed more controlled substances as child age increased. Rates of controlled medications prescribed generally increased, as children got older, regardless of provider type. NPs overall prescribe in a similar pattern to physicians when given the authority to prescribe controlled substances for ADHD. Comparisons between prescriber types for controlled substance prescribing by age should be explored further to identify possible variance from national guidelines.
NASA Technical Reports Server (NTRS)
Billings, W. W.
1981-01-01
Three types of solid state power controllers (SSPC's) for high voltage, high power DC system applications were developed. The first type utilizes a SCR power switch. The second type employes an electromechanical power switch element with solid state commutation. The third type utilizes a transistor power switch. Significant accomplishments include high operating efficiencies, fault clearing, high/low temperature performance and vacuum operation.
Typing Local Control and State Using Flow Analysis
NASA Astrophysics Data System (ADS)
Guha, Arjun; Saftoiu, Claudiu; Krishnamurthi, Shriram
Programs written in scripting languages employ idioms that confound conventional type systems. In this paper, we highlight one important set of related idioms: the use of local control and state to reason informally about types. To address these idioms, we formalize run-time tags and their relationship to types, and use these to present a novel strategy to integrate typing with flow analysis in a modular way. We demonstrate that in our separation of typing and flow analysis, each component remains conventional, their composition is simple, but the result can handle these idioms better than either one alone.
Adaptive kanban control mechanism for a single-stage hybrid system
NASA Astrophysics Data System (ADS)
Korugan, Aybek; Gupta, Surendra M.
2002-02-01
In this paper, we consider a hybrid manufacturing system with two discrete production lines. Here the output of either production line can satisfy the demand for the same type of product without any penalties. The interarrival times for demand occurrences and service completions are exponentially distributed i.i.d. variables. In order to control this type of manufacturing system we suggest a single stage pull type control mechanism with adaptive kanbans and state independent routing of the production information.
Green, Paul E; Woodrooffe, John
2006-01-01
Using data from the NASS General Estimates System (GES), the method of induced exposure was used to assess the effects of electronic stability control (ESC) on loss-of-control type crashes for sport utility vehicles. Sport utility vehicles were classified into crash types generally associated with loss of control and crash types most likely not associated with loss of control. Vehicles were then compared as to whether ESC technology was present or absent in the vehicles. A generalized additive model was fit to assess the effects of ESC, driver age, and driver gender on the odds of loss of control. In addition, the effects of ESC on roads that were not dry were compared to effects on roads that were dry. Overall, the estimated percentage reduction in the odds of a loss-of-control crash for sport utility vehicles equipped with ESC was 70.3%. Both genders and all age groups showed reduced odds of loss-of-control crashes, but there was no significant difference between males and females. With respect to driver age, the maximum percentage reduction of 73.6% occurred at age 27. The positive effects of ESC on roads that were not dry were significantly greater than on roads that were dry.
Type-2 fuzzy logic control of a 2-DOF helicopter (TRMS system)
NASA Astrophysics Data System (ADS)
Zeghlache, Samir; Kara, Kamel; Saigaa, Djamel
2014-09-01
The helicopter dynamic includes nonlinearities, parametric uncertainties and is subject to unknown external disturbances. Such complicated dynamics involve designing sophisticated control algorithms that can deal with these difficulties. In this paper, a type 2 fuzzy logic PID controller is proposed for TRMS (twin rotor mimo system) control problem. Using triangular membership functions and based on a human operator experience, two controllers are designed to control the position of the yaw and the pitch angles of the TRMS. Simulation results are given to illustrate the effectiveness of the proposed control scheme.
Control of gill ventilation and air-breathing in the bowfin amia calva
Hedrick; Jones
1999-01-01
The purpose of this study was to investigate the roles of branchial and gas bladder reflex pathways in the control of gill ventilation and air-breathing in the bowfin Amia calva. We have previously determined that bowfin use two distinct air-breathing mechanisms to ventilate the gas bladder: type I air breaths are characterized by exhalation followed by inhalation, are stimulated by aquatic or aerial hypoxia and appear to regulate O2 gas exchange; type II air breaths are characterized by inhalation alone and possibly regulate gas bladder volume and buoyancy. In the present study, we test the hypotheses (1) that gill ventilation and type I air breaths are controlled by O2-sensitive chemoreceptors located in the branchial region, and (2) that type II air breaths are controlled by gas bladder mechanosensitive stretch receptors. Hypothesis 1 was tested by examining the effects of partial or complete branchial denervation of cranial nerves IX and X to the gill arches on gill ventilation frequency (fg) and the proportion of type I air breaths during normoxia and hypoxia; hypothesis II was tested by gas bladder inflation and deflation. Following complete bilateral branchial denervation, fg did not differ from that of sham-operated control fish; in addition, fg was not significantly affected by aquatic hypoxia in sham-operated or denervated fish. In sham-operated fish, aquatic hypoxia significantly increased overall air-breathing frequency (fab) and the percentage of type I breaths. In fish with complete IX-X branchial denervation, fab was also significantly increased during aquatic hypoxia, but there were equal percentages of type I and type II air breaths. Branchial denervation did not affect the frequency of type I air breaths during aquatic hypoxia. Gas bladder deflation via an indwelling catheter resulted in type II breaths almost exclusively; furthermore, fab was significantly correlated with the volume removed from the gas bladder, suggesting a volume-regulating function for type II air breaths. These results indicate that chronic (3-4 weeks) branchial denervation does not significantly affect fg or type I air-breathing responses to aquatic hypoxia. Because type I air-breathing responses to aquatic hypoxia persist after IX-X cranial nerve denervation, O2-sensitive chemoreceptors that regulate air-breathing may be carried in other afferent pathways, such as the pseudobranch. Gas bladder deflation reflexly stimulates type II breaths, suggesting that gas bladder volume-sensitive stretch receptors control this particular air-breathing mechanism. It is likely that type II air breaths function to regulate buoyancy when gas bladder volume declines during the inter-breath interval.
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Effects of immobilization and whole-body vibration on rat serum Type I collagen turnover.
Dönmez, Gürhan; Doral, Mahmut Nedim; Suljevic, Şenay; Sargon, Mustafa Fevzi; Bilgili, Hasan; Demirel, Haydar Ali
2016-08-01
The aim of this study was to investigate the effects of short-term, high-magnitude whole-body vibration (WBV) on serum type I collagen turnover in immobilized rats. Thirty Wistar albino rats were randomly divided into the following 5 groups: immobilization (IS), immobilization + remobilization (IR), immobilization + WBV (IV), control (C), and WBV control (CV). Immobilization was achieved by casting from the crista iliaca anterior superior to the lower part of the foot for 2 weeks. The applied WBV protocol involved a frequency of 45 Hz and amplitude of 3 mm for 7 days starting a day after the end of the immobilization period. Serum type I collagen turnover markers were measured by using ELISA kits. Serum NH2-terminal propeptide of type I collagen (PINP) levels were significantly lower in the immobilization groups (p < 0.02) compared with the control groups. Although WBV improved PINP levels in the control groups, there were no differences in PINP levels among the immobilization groups. Similarly, serum COOH-terminal telopeptide of type I collagen (CTX) levels were higher in the WBV controls than their own controls (p < 0,05). Immobilization led to deterioration of tendon tissue, as observed by histopathological analysis with a transmission electron microscope. Although 1 week of WBV had a positive effect on type I collagen turnover in controls, it is not an efficient method for repairing tissue damage in the early stage following immobilization. Copyright © 2016 Turkish Association of Orthopaedics and Traumatology. Production and hosting by Elsevier B.V. All rights reserved.
Evaluation of random plasma glucose for assessment of glycaemic control in type 2 diabetes mellitus.
Ain, Qurratul; Latif, Atif; Jaffar, Syed Raza; Ijaz, Aamir
2017-09-01
To evaluate the accuracy of random plasma glucose in outpatients with type 2 diabetes mellitus for assessing glycaemic control. This comparative, cross-sectional study was conducted at the chemical pathology department of PNS Shifa Hospital, Karachi, from August 2015 to March 2016, and comprised data of subjects with type 2 diabetes mellitus who reported for evaluation of glycaemic control in non-fasting state. All blood samples were analysed for random plasma glucose and glycated haemoglobin. Random plasma glucose was compared as an index test with glycated haemoglobin considering it as reference standard at a value of less than 7% for good glycaemic control. SPSS 20 was used for data analysis. Of the 222 subjects, 93(42%) had good glycaemic control. Random plasma glucose showed strong positive correlation with glycated haemoglobin (p=0.000).Area under curve for random plasma glucose as determined by plotting receiver operating characteristic curve against glycated haemoglobin value of 7% was 0.89 (95% confidence interval: 0.849-0.930). Random plasma glucose at cut-off value of 150 mg/dl was most efficient for ruling out poor glycaemic control among patients with type 2 diabetes mellitus with 90.7% sensitivity and69.9% specificity and Youden's index of 0.606. Random plasma glucose may be used to reflect glycaemic control in adults with type 2 diabetes mellitus in areas where glycated haemoglobin is not feasible.
Ahmed, Magdy R; Shaaban, Mohamed M; Sedik, Wael F; Mohamed, Tamer Y
2017-04-24
To evaluate the female sexual dysfunction in both type 1 and type 2 diabetes mellitus (DM). This cross-sectional study was carried out at Suez Canal University Hospitals from the start of February 2015 to the end of May 2016 among 189 married premenopausal women attending endocrinology and diabetology outpatient clinic for regular follow-up; 25 of whom refused to participate and 18 more were excluded due to incomplete data sets resulting in a final sample of 146 diabetic females. Ninety healthy women were recruited from the administrative staff at the hospital as a control group. Sexual dysfunction was assessed using female sexual function index (FSFI), a validated 19-item, self-administered, screening questionnaire comprising the six major sexual domains: desire, arousal, lubrication, orgasm, satisfaction and pain. Responses to each question were reported and scored on 0-5 scale with 0 representing no sexual activity and 5 suggestive of normal sexual activity. Prevalence of sexual dysfunction was significantly higher in both type 1 and 2 DM groups (44 and 25%, respectively) than in the control group (9%). FSFI mean total score was significantly lower in type 1 DM (21.1 ± 3.9) than type 2 DM (26.4 ± 4.2) and both were significantly lower than the control group (31.5 ± 5.8). With regard to FSFI domains, mean values for desire, arousal, lubrication, orgasm, satisfaction and pain were significantly lower in both type 1 and type 2 DM groups when compared with the controls. FSD is a significant health problem among premenopausal diabetic Egyptian women. Type 1 DM women were more affected than type 2 DM that in turn was more affected than healthy control females.
Compromised quality of life in patients with both Type 1 diabetes mellitus and coeliac disease.
Bakker, S F; Pouwer, F; Tushuizen, M E; Hoogma, R P; Mulder, C J; Simsek, S
2013-07-01
Type 1 diabetes mellitus and coeliac disease are two chronic illnesses associated with each other. Both diseases and their treatments can seriously impair quality of life. The objective of the present study was to investigate health-related quality of life in adult patients diagnosed with both Type 1 diabetes and coeliac disease and compare this with healthy control subjects and control subjects who have Type 1 diabetes only. A generic measure of health-related quality of life (RAND-36) and a measure of diabetes-specific quality of life (DQOL) questionnaires were sent to patients diagnosed with both Type 1 diabetes and coeliac disease. The control group consisted of patients with Type 1 diabetes without coeliac disease matched for age, gender and socio-economic status. Generic quality of life scores were compared with data from healthy Dutch control subjects. Fifty-seven patients with Type 1 diabetes and coeliac disease were included and no associations between clinical characteristics and quality of life were observed. Women reported a lower quality of life in social functioning, vitality and mental health than men (all P < 0.05). A lower diabetes-specific quality of life was observed regarding diabetes-related worries and social worries in patients with Type 1 diabetes and coeliac disease compared with patients with Type 1 diabetes. Compared with healthy control subjects, quality of life in patients with Type 1 diabetes and coeliac disease was significantly lower, particularly social functioning (Cohen's d = 0.76) and general health perception (Cohen's d = 0.86). The additional diagnosis of coeliac disease and treatment by gluten-free diet in adult patients with Type 1 diabetes has a considerable, negative impact on quality of life and diabetes-specific quality of life. Women are particularly affected and social functioning and general health perception is compromised. © 2013 The Authors. Diabetic Medicine © 2013 Diabetes UK.
NASA Technical Reports Server (NTRS)
Braslow, A. L.
1999-01-01
The paper contains the following sections: Foreword; Preface; Laminar-Flow Control Concepts and Scope of Monograph; Early Research on Suction-Type Laminar-Flow Control (Research from the 1930s through the War Years; Research from after World War II to the Mid-1960s); Post X-21 Research on Suction-Type Laminar-Flow Control; Status of Laminar-Flow Control Technology in the Mid-1990s; Glossary; Document 1-Aeronautics Panel, AACB, R&D Review, Report of the Subpanel on Aeronautic Energy Conservation/Fuels; Document 2-Report of Review Group on X-21A Laminar Flow Control Program; Document 3-Langley Research Center Announcement, Establishment of Laminar Flow Control Working Group; Document 4-Intercenter Agreement for Laminar Flow Control Leading Edge Glove Flights, LaRC and DFRC; Document 5-Flight Report NLF-144, of AFTIF-111 Aircraft with the TACT Wing Modified by a Natural Laminar Flow Glove; Document 6-Flight Record, F-16XL Supersonic Laminar Flow Control Aircraft; Index; and About the Author.
Vurdem, Ümit Erkan; Acer, Niyazi; Ertekin, Tolga; Savranlar, Ahmet; İnci, Mehmet Fatih
2012-01-01
Objective. The aim of this study was to determine the posterior cranial fossa volume, cerebellar volume, and herniated tonsillar volume in patients with chiari type I malformation and control subjects using stereological methods. Material and Methods. These volumes were estimated retrospectively using the Cavalieri principle as a point-counting technique. We used magnetic resonance images taken from 25 control subjects and 30 patients with chiari type I malformation. Results. The posterior cranial fossa volume in patients with chiari type I malformation was significantly smaller than the volume in the control subjects (P < 0.05). In the chiari type I malformation group, the cerebellar volume was smaller than the control group, but this difference was not statistically significant (P > 0.05). In the chiari type I malformation group, the ratio of cerebellar volume to posterior cranial fossa volume was higher than in the control group. We also found a positive correlation between the posterior cranial fossa volume and cerebellar volume for each of the groups (r = 0.865, P < 0.001). The mean (±SD) herniated tonsillar volume and length were 0.89 ± 0.50 cm3 and 9.63 ± 3.37 mm in the chiari type I malformation group, respectively. Conclusion. This study has shown that posterior cranial fossa and cerebellum volumes can be measured by stereological methods, and the ratio of these measurements can contribute to the evaluation of chiari type I malformation cases. PMID:22629166
Simulation of proportional control of hydraulic actuator using digital hydraulic valves
NASA Astrophysics Data System (ADS)
Raghuraman, D. R. S.; Senthil Kumar, S.; Kalaiarasan, G.
2017-11-01
Fluid power systems using oil hydraulics in earth moving and construction equipment have been using proportional and servo control valves for a long time to achieve precise and accurate position control backed by system performance. Such valves are having feedback control in them and exhibit good response, sensitivity and fine control of the actuators. Servo valves and proportional valves are possessing less hysteresis when compared to on-off type valves, but when the servo valve spools get stuck in one position, a high frequency called as jitter is employed to bring the spool back, whereas in on-off type valves it requires lesser technology to retract the spool. Hence on-off type valves are used in a technology known as digital valve technology, which caters to precise control on slow moving loads with fast switching times and with good flow and pressure control mimicking the performance of an equivalent “proportional valve” or “servo valve”.
Role of parenting style in achieving metabolic control in adolescents with type 1 diabetes.
Shorer, Maayan; David, Ravit; Schoenberg-Taz, Michal; Levavi-Lavi, Ifat; Phillip, Moshe; Meyerovitch, Joseph
2011-08-01
To examine the role of parenting style in achieving metabolic control and treatment adherence in adolescents with type 1 diabetes. Parents of 100 adolescents with type 1 diabetes completed assessments of their parenting style and sense of helplessness. Parents and patients rated patient adherence to the treatment regimen. Glycemic control was evaluated by HbA(1c) values. An authoritative paternal parenting style predicted better glycemic control and adherence in the child; a permissive maternal parenting style predicted poor adherence. A higher sense of helplessness in both parents predicted worse glycemic control and lesser adherence to treatment. Parental sense of helplessness was a significant predictor of diabetes control after correcting for other confounders (patient age, sex, and treatment method). An authoritative nonhelpless parenting style is associated with better diabetes control in adolescents. Paternal involvement is important in adolescent diabetes management. These results have implications for psychological interventions.
Cheng, Shi-Hui; Ismail, Amin; Anthony, Joseph; Ng, Ooi Chuan; Hamid, Azizah Abdul; Barakatun-Nisak, Mohd Yusof
2015-01-01
Objectives. Optimizing glycemic control is crucial to prevent type 2 diabetes related complications. Cosmos caudatus is reported to have promising effect in improving plasma blood glucose in an animal model. However, its impact on human remains ambiguous. This study was carried out to evaluate the effectiveness of C. caudatus on glycemic status in patients with type 2 diabetes. Materials and Methods. In this randomized controlled trial with two-arm parallel-group design, a total of 101 subjects with type 2 diabetes were randomly allocated to diabetic-ulam or diabetic controls for eight weeks. Subjects in diabetic-ulam group consumed 15 g of C. caudatus daily for eight weeks while diabetic controls abstained from taking C. caudatus. Both groups received the standard lifestyle advice. Results. After 8 weeks of supplementation, C. caudatus significantly reduced serum insulin (-1.16 versus +3.91), reduced HOMA-IR (-1.09 versus +1.34), and increased QUICKI (+0.05 versus -0.03) in diabetic-ulam group compared with the diabetic controls. HbA1C level was improved although it is not statistically significant (-0.76% versus -0.37%). C. caudatus was safe to consume. Conclusions. C. caudatus supplementation significantly improves insulin resistance and insulin sensitivity in patients with type 2 diabetes.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Itoh, H.; Akashi, T.; Takada, M.
1987-03-31
This patent describes a hydraulic control system for controlling a speed ratio of a hydraulically-operated continuously variable transmission of belt-and-pulley type having a variable-diameter pulley and a hydraulic cylinder for changing an effective diameter of the variable diameter-pulley of the transmission. The hydraulic control system includes a speed-ratio control valve assembly for controlling the supply and discharge of a pressurized fluid to and from the hydraulic cylinder to thereby change the speed ratio of the transmission. The speed-ratio control valve assembly comprises: a shift-direction switching valve unit disposed in fluid supply and discharge conduits communicating with the hydraulic cylinder, formore » controlling a direction in which the speed ratio of the transmission is varied; a shift-speed control valve unit of spool-valve type connected to the shift-direction switching valve unit. The shift-speed control valve unit is selectively placed in a first state in which the fluid supply and discharge flows to and from the hydraulic cylinder through the conduits are permitted, or in a second state in which the fluid supply flow is restricted while the fluid discharge flow is inhibited; an actuator means for placing the shift speed control valve unit alternately in the first and second states to control a rate of variation in the speed ratio of the transmission in the direction established by the shift-direction switching valve unit.« less
USDA-ARS?s Scientific Manuscript database
Previous studies assessing the effect of metformin on glycemic control in adolescents with type 1 diabetes have produced inconclusive results. To assess the efficacy and safety of metformin as an adjunct to insulin in treating overweight adolescents with type 1 diabetes. Multicenter (26 pediatric en...
14 CFR 135.247 - Pilot qualifications: Recent experience.
Code of Federal Regulations, 2014 CFR
2014-01-01
... as the sole manipulator of the flight controls in an aircraft of the same category and class and, if... controls in an aircraft of the same category and class and, if a type rating is required, of the same type... to a pilot in command of a turbine-powered airplane that is type certificated for more than one pilot...
14 CFR 135.247 - Pilot qualifications: Recent experience.
Code of Federal Regulations, 2013 CFR
2013-01-01
... as the sole manipulator of the flight controls in an aircraft of the same category and class and, if... controls in an aircraft of the same category and class and, if a type rating is required, of the same type... to a pilot in command of a turbine-powered airplane that is type certificated for more than one pilot...
14 CFR 135.247 - Pilot qualifications: Recent experience.
Code of Federal Regulations, 2012 CFR
2012-01-01
... as the sole manipulator of the flight controls in an aircraft of the same category and class and, if... controls in an aircraft of the same category and class and, if a type rating is required, of the same type... to a pilot in command of a turbine-powered airplane that is type certificated for more than one pilot...
A Relentless Illness—Fighting Diabetes
... in the fight to control and cure type 1 diabetes. As international chairman of the Juvenile Diabetes Research ... advances in the understanding and treatment of type 1 diabetes—even as she has fought to control her ...
Controlled n-Type Doping of Carbon Nanotube Transistors by an Organorhodium Dimer.
Geier, Michael L; Moudgil, Karttikay; Barlow, Stephen; Marder, Seth R; Hersam, Mark C
2016-07-13
Single-walled carbon nanotube (SWCNT) transistors are among the most developed nanoelectronic devices for high-performance computing applications. While p-type SWCNT transistors are easily achieved through adventitious adsorption of atmospheric oxygen, n-type SWCNT transistors require extrinsic doping schemes. Existing n-type doping strategies for SWCNT transistors suffer from one or more issues including environmental instability, limited carrier concentration modulation, undesirable threshold voltage control, and/or poor morphology. In particular, commonly employed benzyl viologen n-type doping layers possess large thicknesses, which preclude top-gate transistor designs that underlie high-density integrated circuit layouts. To overcome these limitations, we report here the controlled n-type doping of SWCNT thin-film transistors with a solution-processed pentamethylrhodocene dimer. The charge transport properties of organorhodium-treated SWCNT thin films show consistent n-type behavior when characterized in both Hall effect and thin-film transistor geometries. Due to the molecular-scale thickness of the organorhodium adlayer, large-area arrays of top-gated, n-type SWCNT transistors are fabricated with high yield. This work will thus facilitate ongoing efforts to realize high-density SWCNT integrated circuits.
How to Identify and Control Water Weeds and Algae.
ERIC Educational Resources Information Center
Applied Biochemists, Inc., Mequon, WI.
Included in this guide to water management are general descriptions of algae, toxic algae, weed problems in lakes, ponds, and canals, and general discussions of mechanical, biological and chemical control methods. In addition, pictures, descriptions, and recommended control methods are given for algae, 6 types of floating weeds, 18 types of…
The Development of Two Types of Inhibitory Control in Monolingual and Bilingual Children
ERIC Educational Resources Information Center
Martin-Rhee, Michelle M.; Bialystok, Ellen
2008-01-01
Previous research has shown that bilingual children excel in tasks requiring inhibitory control to ignore a misleading perceptual cue. The present series of studies extends this finding by identifying the degree and type of inhibitory control for which bilingual children demonstrate this advantage. Study 1 replicated the earlier research by…
Compact, Lightweight Servo-Controllable Brakes
NASA Technical Reports Server (NTRS)
Lovchik, Christopher S.; Townsend, William; Guertin, Jeffrey; Matsuoka, Yoky
2010-01-01
Compact, lightweight servo-controllable brakes capable of high torques are being developed for incorporation into robot joints. A brake of this type is based partly on the capstan effect of tension elements. In a brake of the type under development, a controllable intermediate state of torque is reached through on/off switching at a high frequency.
Interaction between Sex and Social Support in the Control of Type II Diabetes Mellitus.
ERIC Educational Resources Information Center
Heitzmann, Carma A.; Kaplan, Robert M.
1984-01-01
Investigated the role of social support in the control of Type II diabetes mellitus. Participants (N=37) in a behavioral program in diabetes care completed questionnaires and provided blood samples. For women, satisfaction with supportive relationships was associated with control of diabetes. The opposite was true for men. (BH)
Wheelset curving guidance using H∞ control
NASA Astrophysics Data System (ADS)
Qazizadeh, Alireza; Stichel, Sebastian; Feyzmahdavian, Hamid Reza
2018-03-01
This study shows how to design an active suspension system for guidance of a rail vehicle wheelset in curve. The main focus of the study is on designing the controller and afterwards studying its effect on the wheel wear behaviour. The controller is designed based on the closed-loop transfer function shaping method and ? control strategy. The study discusses designing of the controller for both nominal and uncertain plants and considers both stability and performance. The designed controllers in Simulink are then applied to the vehicle model in Simpack to study the wheel wear behaviour in curve. The vehicle type selected for this study is a two-axle rail vehicle. This is because this type of vehicle is known to have very poor curving performance and high wheel wear. On the other hand, the relative simpler structure of this type of vehicle compared to bogie vehicles make it a more economic choice. Hence, equipping this type of vehicle with the active wheelset steering is believed to show high enough benefit to cost ratio to remain attractive to rail vehicle manufacturers and operators.
NASA Technical Reports Server (NTRS)
Sorenson, R. L.; Steger, J. L.
1980-01-01
A method for generating boundary-fitted, curvilinear, two dimensional grids by the use of the Poisson equations is presented. Grids of C-type and O-type were made about airfoils and other shapes, with circular, rectangular, cascade-type, and other outer boundary shapes. Both viscous and inviscid spacings were used. In all cases, two important types of grid control can be exercised at both inner and outer boundaries. First is arbitrary control of the distances between the boundaries and the adjacent lines of the same coordinate family, i.e., stand-off distances. Second is arbitrary control of the angles with which lines of the opposite coordinate family intersect the boundaries. Thus, both grid cell size (or aspect ratio) and grid cell skewness are controlled at boundaries. Reasonable cell size and shape are ensured even in cases wherein extreme boundary shapes would tend to cause skewness or poorly controlled grid spacing. An inherent feature of the Poisson equations is that lines in the interior of the grid smoothly connect the boundary points (the grid mapping functions are second order differentiable).
Ji, Linong; Hu, Dayi; Pan, Changyu; Weng, Jianping; Huo, Yong; Ma, Changsheng; Mu, Yiming; Hao, Chuanming; Ji, Qiuhe; Ran, Xingwu; Su, Benli; Zhuo, Hanjing; Fox, Keith A A; Weber, Michael; Zhang, Danyi
2013-10-01
Individually, diabetes mellitus, hypertension, and dyslipidemia have been shown to increase the risk of cardiovascular disease. While traditional management of Type 2 diabetes has focused mainly on glycemic control, robust evidence supports the integration of hypertension and dyslipidemia management to reduce the risk of cardiovascular disease. The primary objective of this study was to assess the level of control of blood glucose, blood pressure, and blood lipids (3Bs) among patients with type 2 diabetes. An additional objective was to investigate the impact of hospital type, physician specialty, treatment pattern, and patient profile on clinical outcomes. This was a cross-sectional, multicenter observational study. A nationally representative sample of outpatients with established type 2 diabetes were enrolled at hospitals representative of geographic regions, tiers, and physician specialties in China. Main clinical measurements were the levels of glycosylated hemoglobin (HbA1c), blood pressure, and total serum cholesterol in reference to target goals. A total of 25,817 adults with type 2 diabetes (mean age 62.6 years, 47% male) were enrolled at 104 hospitals. Seventy-two percent reported comorbid hypertension, dyslipidemia, or both. Patients with concurrent type 2 diabetes, hypertension, and dyslipidemia were 6 times more likely to report a prior history of cardiovascular disease compared with those with type 2 diabetes alone. The mean HbA1c level was 7.6%. While 47.7%, 28.4%, and 36.1% of patients achieved the individual target goals for control of blood glucose (HbA1c <7%), blood pressure (systolic blood pressure <130 mm Hg, diastolic blood pressure <80 mm Hg), and blood lipids (total cholesterol <4.5 mmol/L), respectively, only 5.6% achieved all 3 target goals. Lower body mass index (<24 kg/m(2)), no active smoking or drinking, higher education, and diabetes duration <5 years were independent predictors of better cardiovascular disease risk control. Achieving adequate control of risk factors for cardiovascular disease in patients with type 2 diabetes remains a clinical challenge. Interventions to achieve control of 3Bs coupled with modification of additional cardiovascular disease predictors are crucial for optimization of clinical outcomes in patients with type 2 diabetes. Copyright © 2013 Elsevier Inc. All rights reserved.
Horvath, Frank; Palmatier, John J
2008-07-01
Two major variations of polygraph "Control Question" testing, the Zone Comparison (ZoC) and the Modified General Question Test (MGQT) were evaluated. Within each, the type of control question, Exclusive or "time bar" (e.g., "Before you were 21, did you ever...") and Nonexclusive or "no time bar" (e.g., "Did you ever....?") was manipulated in a mock theft scenario, with 80 male and 40 female subjects randomly assigned to be either innocent or guilty. Polygraphic data collected by experienced field examiners were numerically scored by an evaluator blind to all aspects of the study. Decision accuracy was not related to the type of procedure (ZoC/MGQT) used or the subject's sex. Accuracy was significantly related to the type of control question [chi(2) (2) = 11.46, p = 0.003; tau c = 0.29]. Nonexclusive control questions produced greater accuracy than Exclusive control questions on both innocent and guilty subjects. These results and subjects' self-reports support the general "theory" on which control question (CQ) testing is based. The need for better empirical support of accepted dogma and current field practices is strongly indicated by these findings.
NASA Astrophysics Data System (ADS)
Goo, Yong Sook; Ye, Jang Hee; Lee, Seokyoung; Nam, Yoonkey; Ryu, Sang Baek; Kim, Kyung Hwan
2011-06-01
Retinal prostheses are being developed to restore vision for those with retinal diseases such as retinitis pigmentosa or age-related macular degeneration. Since neural prostheses depend upon electrical stimulation to control neural activity, optimal stimulation parameters for successful encoding of visual information are one of the most important requirements to enable visual perception. In this paper, we focused on retinal ganglion cell (RGC) responses to different stimulation parameters and compared threshold charge densities in wild-type and rd1 mice. For this purpose, we used in vitro retinal preparations of wild-type and rd1 mice. When the neural network was stimulated with voltage- and current-controlled pulses, RGCs from both wild-type and rd1 mice responded; however the temporal pattern of RGC response is very different. In wild-type RGCs, a single peak within 100 ms appears, while multiple peaks (approximately four peaks) with ~10 Hz rhythm within 400 ms appear in RGCs in the degenerated retina of rd1 mice. We find that an anodic phase-first biphasic voltage-controlled pulse is more efficient for stimulation than a biphasic current-controlled pulse based on lower threshold charge density. The threshold charge densities for activation of RGCs both with voltage- and current-controlled pulses are overall more elevated for the rd1 mouse than the wild-type mouse. Here, we propose the stimulus range for wild-type and rd1 retinas when the optimal modulation of a RGC response is possible.
Influence of complete spinal cord injury on skeletal muscle within 6 mo of injury.
Castro, M J; Apple, D F; Staron, R S; Campos, G E; Dudley, G A
1999-01-01
This study examined the influence of spinal cord injury (SCI) on affected skeletal muscle. The right vastus lateralis muscle was biopsied in 12 patients as soon as they were clinically stable (average 6 wk after SCI), and 11 and 24 wk after injury. Samples were also taken from nine able-bodied controls at two time points 18 wk apart. Surface electrical stimulation (ES) was applied to the left quadriceps femoris muscle to assess fatigue at these same time intervals. Biopsies were analyzed for fiber type percent and cross-sectional area (CSA), fiber type-specific succinic dehydrogenase (SDH) and alpha-glycerophosphate dehydrogenase (GPDH) activities, and myosin heavy chain percent. Controls showed no change in any variable over time. Patients showed 27-56% atrophy (P = 0.000) of type I, IIa, and IIax+IIx fibers from 6 to 24 wk after injury, resulting in fiber CSA approximately one-third that of controls. Their fiber type specific SDH and GPDH activities increased (P = 0.001) from 32 to 90% over the 18 wk, thereby approaching or surpassing control values. The relative CSA of type I fibers and percentage of myosin heavy chain type I did not change. There was apparent conversion among type II fiber subtypes; type IIa decreased and type IIax+IIx increased (P = 0.012). Force loss during ES did not change over time for either group but was greater (P = 0.000) for SCI patients than for controls overall (27 vs. 9%). The results indicate that vastus lateralis muscle shows marked fiber atrophy, no change in the proportion of type I fibers, and a relative independence of metabolic enzyme levels from activation during the first 24 wk after clinically complete SCI. Over this time, quadriceps femoris muscle showed moderately greater force loss during ES in patients than in controls. It is suggested that the predominant response of mixed human skeletal muscle within 6 mo of SCI is loss of contractile protein. Therapeutic interventions could take advantage of this to increase muscle mass.
The impact of diabetes mellitus on the course and outcome of pregnancy during a 5-year follow-up.
Mitrović, Milena; Stojić, Siniša; Tešić, Dragan S; Popović, Djordje; Rankov, Olivera; Naglić, Dragana Tomić; Paro, Jovanka Novaković; Pejin, Radoslav; Bulatović, Sanja; Veljić, Mašsa Todorović; Zavišić, Branka Kovarev
2014-10-01
Women with diabetes, especially diabetes type 1, have worse pregnancy outcomes, as well as increased incidence of spontaneous abortions, pre-eclampsia, fetal macrosomia, preterm delivery, congenital anomalies and perinatal mortality. The aim of this study was to analyze the course and outcome of pregnancy in the patients with diabetes in relation to the group of healthy women regarding preterm delivery, perinatal morbidity and mortality. Also, the aim was to compare pregnancy outcomes in the patients with pre-existing diabetes type 1 and the patients with gestational and diabetes type 2. This retrospective study included 156 diabetic women treated at the Clinic of Endocrinology, Diabetes and Metabolic Diseases and Gynecology and Obstetrics Clinic of the Clinical Center of Vojvodina from 2006 to 2010. There were 94 patients with gestational diabetes, 48 with type 1 diabetes, and 14 patients with type 2 diabetes. The control group included 106 healthy women hospitalized at the Gynecology and Obstetrics Clinic. The women with type 1 diabetes presented with a statistically significantly higher incidence of cesarean section than those without diabetes, or with type 2 or gestational diabetes (p < 0.0001); the women with type 1 diabetes delivered at an earlier week of gestation (WG) in regard to women without diabetes, or with type 2 or gestational diabetes (p = 0.0017 and p = 0.02, respectively). The incidence of perinatal morbidity: hypoglycemia (p < 0.001), pathological jaundice (p = 0.0021), and other neonatal pathologies at birth (p = 0.0031), was statistically significantly higher and Apgar scores after 1 minute (p = 0.0142) and after 5 minutes (p = 0.0003) were statistically significantly lower in the patients with diabetes compared to the healthy women. The women with type 2 and gestational diabetes were statistically significantly older than those with type 1 diabetes (p = 0.001). A higher incidence of fetal macrosomia in the women with gestational and type 2 diabetes compared to those with type 1 diabetes was at the borderline of statistical significance (p = 0.07), whereas the incidence of hypoglycemia of newborn was statistically significantly higher in the patients with type 1 diabetes (p < 0.0001). Glycosylated hemoglobin (HbA1c) levels were statistically significantly higher in the diabetic women giving birth during and before the week of gestation 36 (p = 0.0087), but there were no differences in HbA1lc levels in regard to fetal macrosomia (p = 0.45) and congenital abnormalities (p = 0.32). The results of our study show a higher incidence of perinatal fetal morbidity (hypoglycemia, jaundice, respiratory distress syndrome) in the patients with type 1, type 2 and gestation diabetes than in the healthy controls. Also, we found a higher incidence of cesarean section in the patients with type 1 diabetes than in those with type 2, gestation diabetes and healthy controls. Although delivery in the patients with type 1, type 2 and gestational diabetes was completed approximately one to two weeks earlier compared to the healthy controls there was no statistically significant difference in the incidence of preterm delivery (≤ 36th week of gestation) between the women with diabetes and healthy controls. Preterm delivery associated with poorer glycaemic control reflected through higher values of HbA1c in third trimester. Risks from adverse pregnancy outcomes may be reduced to minimum by adequate preconception counseling of diabetic patients and early diagnosis of diabetes in pregnancy, in order to achieve glycemic control during organogenesis and within pregnancy and through the teamwork of endocrinologists, gynecologists and pediatricians.
Franklin R. Ward; David V. Sandberg
1981-01-01
This publication presents tables on the behavior of fire and the resistance: of fuels to control. The information is to be used with the photos in the publication, "Photo Series for Quantifying Forest Residues in the Sierra Mixed Conifer Type, Sierra True Fir Type" (Maxwell, Wayne G.; Ward, Franklin R. 1979. Gen. Tech. Rep. PNW-GTR-095. Portland, OR: U.S....
Evaluation of salivary glucose, IgA and flow rate in diabetic patients: a case-control study.
Bakianian Vaziri, P; Vahedi, M; Mortazavi, H; Abdollahzadeh, Sh; Hajilooi, M
2010-01-01
An association between diabetes mellitus and alterations in the oral cavity has been noted. In this study, we evaluated differences between salivary IgA, glucose and flow rate in diabetic patients compared with healthy controls. Forty patients with type 1 diabetes, 40 patients with type 2 diabetes and 40 healthy controls were selected. Whole unstimulated saliva samples were collected by the standard method and the salivary flow rate was determined. Nephelometric and Pars method were used to measure salivary IgA and salivary glucose concentrations, respectively. Statistical analysis was performed by Chi-square and t test. There were no significant differences in salivary IgA and glucose concentrations between type 1 and type 2 diabetic patients and their matched control subjects (P>0.05). Salivary flow rate was significantly lower in diabetic patients (P<0.05). In addition, DMFT was higher in diabetic patients than the controls. Determination of salivary constituents may be useful in the description and management of oral findings in diabetic patients.
A coordinated control strategy for insulin and glucagon delivery in type 1 diabetes.
Herrero, Pau; Bondia, Jorge; Oliver, Nick; Georgiou, Pantelis
2017-10-01
Type 1 diabetes is an autoimmune condition characterised by a pancreatic insulin secretion deficit, resulting in high blood glucose concentrations, which can lead to micro- and macrovascular complications. Type 1 diabetes also leads to impaired glucagon production by the pancreatic α-cells, which acts as a counter-regulatory hormone to insulin. A closed-loop system for automatic insulin and glucagon delivery, also referred to as an artificial pancreas, has the potential to reduce the self-management burden of type 1 diabetes and reduce the risk of hypo- and hyperglycemia. To date, bihormonal closed-loop systems for glucagon and insulin delivery have been based on two independent controllers. However, in physiology, the secretion of insulin and glucagon in the body is closely interconnected by paracrine and endocrine associations. In this work, we present a novel biologically-inspired glucose control strategy that accounts for such coordination. An in silico study using an FDA-accepted type 1 simulator was performed to evaluate the proposed coordinated control strategy compared to its non-coordinated counterpart, as well as an insulin-only version of the controller. The proposed coordinated strategy achieves a reduction of hyperglycemia without increasing hypoglycemia, when compared to its non-coordinated counterpart.
Sainsbury, Anita; Sanders, David S; Ford, Alexander C
2013-04-01
Patients with celiac disease (CD) often report symptoms compatible with irritable bowel syndrome (IBS). However, the prevalence of these symptoms in patients with CD and their relation to adherence to a gluten-free diet (GFD) have not been assessed systematically. We searched MEDLINE, EMBASE, and EMBASE Classic (through July 2012) to identify cross-sectional surveys or case-control studies reporting prevalence of IBS-type symptoms in adult patients (≥ 16 years old) with established CD. The number of individuals with symptoms meeting criteria for IBS was extracted for each study, according to case or control status and adherence to a GFD. Pooled prevalence and odds ratios (ORs), with 95% confidence intervals (CIs), were calculated. We analyzed data from 7 studies with 3383 participants. The pooled prevalence of IBS-type symptoms in all patients with CD was 38.0% (95% CI, 27.0%-50.0%). The pooled OR for IBS-type symptoms was higher in patients with CD than in controls (5.60; 95% CI, 3.23-9.70). In patients who were nonadherent with a GFD, the pooled OR for IBS-type symptoms, compared with those who were strictly adherent, was 2.69 (95% CI, 0.75-9.56). There was also a trend toward a higher OR for IBS-type symptoms among patients who did not adhere to the GFD, compared with controls (12.42; 95% CI, 6.84-11.75), compared with that observed for adherent CD patients vs controls (4.28; 95% CI, 1.56-11.75). IBS-type symptoms occur frequently in patients with CD and are more common than among controls. Adherence to a GFD might be associated with a reduction in symptoms. Copyright © 2013 AGA Institute. Published by Elsevier Inc. All rights reserved.
Formánek, M; Jančatová, D; Komínek, P; Matoušek, P; Zeleník, K
2017-06-01
The human papillomavirus (HPV) causes recurrent respiratory papillomatosis (RRP). Although HPV prevalence is high, the incidence of papillomatosis is low. Thus, factors other than HPV infection probably contribute to RRP. This study investigated whether patients with papillomatosis are more often infected with herpes simplex virus type 2 and chlamydia trachomatis (ChT) and whether laryngopharyngeal reflux (LPR) occurs in this group of patients more often. Prospective case-control study. Department of Otorhinolaryngology of University Hospital. The study included 20 patients with adult-onset RRP and 20 adult patients with vocal cord cyst and no pathology of laryngeal mucosa (control group). Immunohistochemical analysis of pepsin, HPV, herpes simplex virus type 2 and ChT was performed in biopsy specimens of laryngeal papillomas and of healthy laryngeal mucosa (control group) obtained from medial part of removed vocal cord cyst during microlaryngoscopy procedures. Pathologic LPR (pepsin in tissue) was diagnosed in 8/20 (40.0%) patients with papillomatosis and in 0/20 control patients (P = .003). Herpes simplex virus type 2 was present in 9/20 (45.0%) patients with papillomatosis and in 0/20 control patients (P = .001). Five specimens were positive for both pepsin and herpes simplex virus type 2. No samples were positive for ChT. There were no significant differences between groups for age, body mass index, diabetes mellitus and gastrooesophageal reflux disease. Tobacco exposure was not more frequent in RRP group either (P = .01). Results show that LPR and herpes simplex virus type 2 are significantly more often present in patients with RRP. LPR and herpes simplex virus type 2 might activate latent HPV infection and thereby be possible risk factors for RRP. © 2016 John Wiley & Sons Ltd.
Eisenberg, Miriam H; Lipsky, Leah M; Dempster, Katherine W; Liu, Aiyi; Nansel, Tonja R
2016-11-01
Among adolescents with type 1 diabetes, disordered eating behaviors (DEBs) are more prevalent and have more serious health implications than in adolescents without diabetes, necessitating identification of modifiable correlates of DEB in this population. This study hypothesized that (1) autonomous motivation and (2) controlled motivation for healthy eating (i.e., eating healthfully because it is important to oneself vs. important to others, respectively) are associated with DEB among adolescents with type 1 diabetes. The third hypothesis was that baseline healthy eating self-efficacy moderates these associations. Adolescents with type 1 diabetes (n = 90; 13-16 years) participating in a behavioral nutrition intervention efficacy trial reported DEB, controlled and autonomous motivation, and self-efficacy at baseline, 6, 12, and 18 months. Linear-mixed models estimated associations of controlled and autonomous motivation with DEB, adjusting for treatment group, body mass index, socioeconomic status, age, and gender. Separate models investigated the interaction of self-efficacy with each motivation type. Controlled motivation was positively associated with DEB (B = 2.18 ± .33, p < .001); the association was stronger for those with lower self-efficacy (B = 3.33 ± .55, p < .001) than those with higher self-efficacy (B = 1.36 ± .36, p < .001). Autonomous motivation was not associated with DEB (B = -.70 ± .43, p = .11). Findings identify controlled motivation for healthy eating as a novel correlate of DEB among adolescents with type 1 diabetes and show that self-efficacy can modify this association. Motivation and self-efficacy for healthy eating represent potential intervention targets to reduce DEB in adolescents with type 1 diabetes. Published by Elsevier Inc.
NASA Astrophysics Data System (ADS)
Chen, Dechao; Zhang, Yunong
2017-10-01
Dual-arm redundant robot systems are usually required to handle primary tasks, repetitively and synchronously in practical applications. In this paper, a jerk-level synchronous repetitive motion scheme is proposed to remedy the joint-angle drift phenomenon and achieve the synchronous control of a dual-arm redundant robot system. The proposed scheme is novelly resolved at jerk level, which makes the joint variables, i.e. joint angles, joint velocities and joint accelerations, smooth and bounded. In addition, two types of dynamics algorithms, i.e. gradient-type (G-type) and zeroing-type (Z-type) dynamics algorithms, for the design of repetitive motion variable vectors, are presented in detail with the corresponding circuit schematics. Subsequently, the proposed scheme is reformulated as two dynamical quadratic programs (DQPs) and further integrated into a unified DQP (UDQP) for the synchronous control of a dual-arm robot system. The optimal solution of the UDQP is found by the piecewise-linear projection equation neural network. Moreover, simulations and comparisons based on a six-degrees-of-freedom planar dual-arm redundant robot system substantiate the operation effectiveness and tracking accuracy of the robot system with the proposed scheme for repetitive motion and synchronous control.
Serum proteomics reveals systemic dysregulation of innate immunity in type 1 diabetes
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhang, Qibin; Fillmore, Thomas L.; Schepmoes, Athena A.
Using global liquid chromatography-mass spectrometry (LC-MS)-based proteomics analyses, we identified 24 serum proteins significantly variant between those with type 1 diabetes and healthy controls. Functionally, these proteins represent innate immune responses, the activation cascade of complement, inflammatory responses and blood coagulation. Targeted verification analyses were performed on 52 surrogate peptides representing these proteins with serum samples from an antibody standardization program cohort of 100 healthy control and 50 type 1 diabetic subjects, and 16 peptides were verified having very good discriminating power, with areas under the receiver operator characteristic curve ≥ 0.8. Further validation with blinded serum samples from anmore » independent cohort (10 healthy control and 10 type 1 diabetic) demonstrated that peptides from platelet basic protein and C1 inhibitor achieved both 100% sensitivity and 100% specificity for classification of samples. The disease specificity of these proteins was assessed using serum from 50 age matched type 2 diabetic individuals, and a subset of proteins, particularly C1 inhibitor were exceptionally good discriminators between these two forms of diabetes. The panel of biomarkers distinguishing those with type 1 diabetes from healthy control and type 2 diabetes suggests dysregulated innate immune responses may be associated with the development of this disorder.« less
Interior shadings for office indoor visual comfort in humid climate region
NASA Astrophysics Data System (ADS)
Dinapradipta, Asri; Sudarma, Erwin; Defiana, Ima; Erwindi, Collinthia
2018-03-01
As part of the fenestration system, the interior shadings have also a role to control the indoor environment to maintain indoor visual comfort. As the occupants have personal access to control these, their control behavior then, might enhance or even worsen indoor comfort performance. The controlling behavior might not only influence indoor comfort performance but can also indicate the success or failure of interior shading as a control device element. This paper is intended to report control behavior patterns, as represented by the variety of the slats’ openings of two types of interior shading i.e. Venetian and Vertical blinds and to analyze these on the concurrent impacts to indoor office building’s indoor illuminance and luminance distribution. The purpose of this research is to figure out the shading control patterns as well as to examine the effectiveness of these two types of interior shadings to control indoor visual environment. This study is a quantitative research using experimentation on the slats’ opening of two types of shadings at two identical office rooms. The research results suggested that both types of blinds seem unsuitable for gaining proper illumination values at work planes in humid tropics area. However, these shadings demonstrate good performance for luminance distribution except for that of the closed Venetian blinds.
Quiet Clean Short-haul Experimental Engine (QCSEE) over-the-wing control system design report
NASA Technical Reports Server (NTRS)
1977-01-01
A control system incorporating a digital electronic control was designed for the over-the-wing engine. The digital electronic control serves as the primary controlling element for engine fuel flow and core compressor stator position. It also includes data monitoring capability, a unique failure indication and corrective action feature, and optional provisions for operating with a new type of servovalve designed to operate in response to a digital-type signal and to fail with its output device hydraulically locked into position.
James, Timothy Y.; Srivilai, Prayook; Kües, Ursula; Vilgalys, Rytas
2006-01-01
Mating incompatibility in mushroom fungi is controlled by the mating-type loci. In tetrapolar species, two unlinked mating-type loci exist (A and B), whereas in bipolar species there is only one locus. The A and B mating-type loci encode homeodomain transcription factors and pheromones and pheromone receptors, respectively. Most mushroom species have a tetrapolar mating system, but numerous transitions to bipolar mating systems have occurred. Here we determined the genes controlling mating type in the bipolar mushroom Coprinellus disseminatus. Through positional cloning and degenerate PCR, we sequenced both the transcription factor and pheromone receptor mating-type gene homologs from C. disseminatus. Only the transcription factor genes segregate with mating type, discounting the hypothesis of genetic linkage between the A and B mating-type loci as the causal origin of bipolar mating behavior. The mating-type locus of C. disseminatus is similar to the A mating-type locus of the model species Coprinopsis cinerea and encodes two tightly linked pairs of homeodomain transcription factor genes. When transformed into C. cinerea, the C. disseminatus A and B homologs elicited sexual reactions like native mating-type genes. Although mating type in C. disseminatus is controlled by only the transcription factor genes, cellular functions appear to be conserved for both groups of genes. PMID:16461425
Heideman, Daniëlle A M; Waterboer, Tim; Pawlita, Michael; Delis-van Diemen, Pien; Nindl, Ingo; Leijte, Joost A; Bonfrer, Johannes M G; Horenblas, Simon; Meijer, Chris J L M; Snijders, Peter J F
2007-10-10
Human papillomavirus (HPV) infections are suggested to be involved in the development of penile squamous cell carcinoma (SCC), but comprehensive studies to define the association are limited. Therefore, we performed molecular and serologic analyses for a broad spectrum of HPV types on a large series of 83 penile SCCs, and we compared serological findings to those of age-matched male controls (N = 83). Penile SCCs were subjected to detection and typing assays for mucosal and cutaneous HPVs and to subsequent, type-specific viral load and viral gene expression assays. Sera of patients and of controls were analyzed for type-specific mucosal and cutaneous HPV L1, E6, and/or E7 antibodies using bead-based, multiplex serology. HPV DNA of mucosal and/or cutaneous types was found in 46 of 83 (55%) penile SCCs. HPV16 was the predominant type, appearing in 24 (52%) of 46 of penile SCCs. The majority of HPV16 DNA-positive SCCs (18 of 24; 75%) demonstrated E6 transcriptional activity and a high viral load. Additionally, HPV16 molecular findings were strongly associated with HPV16 L1-, E6-, and E7-antibody seropositivity. Furthermore, serologic case-control analyses demonstrated that, in addition to the association of HPV16 with penile SCC, seropositivity against any HPV type was significantly more common in patients compared with in controls. HPV18 and HPV6 seropositivity were associated with HPV16-negative SCCs but were not correlated to molecular findings. HPV16 is the main HPV type etiologically involved in the development of penile SCC. Although individuals who develop penile SCC show a greater prior exposure to a broad spectrum of HPV types, insufficient evidence was found to claim a role for HPV types other than HPV16 in penile carcinogenesis.
Effect of pH on ethanol-type acidogenic fermentation of fruit and vegetable waste.
Wu, Yuanyuan; Wang, Cuiping; Zheng, Mingyue; Zuo, Jiane; Wu, Jing; Wang, Kaijun; Yang, Boqiong
2017-02-01
The aim of this study was to investigate the possibility and optimal controlling strategy for ethanol-type acidogenic fermentation of fruit and vegetable waste by mixed microbial cultures. Four continuous stirred tank reactors (CSTR) were operated at various pHs (4.0, 5.0, 5.5, and 6.0) with an organic loading rate of 13gVS/(Ld) and hydraulic retention time of 3d. Butyrate-type fermentation was observed at pH 5.0, 5.5, and 6.0. Conversely, at pH 4.0, ethanol-type fermentation was observed with a high mass concentration and proportion (of total fermentative products) of ethanol, which were 6.7g/L and 88.8%, respectively. However, the total concentration of ethanol-type fermentative products substantially decreased from days 22-25. The optimal pH of ethanol-type fermentative microorganisms was investigated by using batch experiments with pH controlled at 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, and 7.0 and results showed that the maximum ethanol concentration and relatively highest acidogenic rate were found at pH of 5.5. The pH in the long term CSTR was changed from 4.0 to 5.5 to improve ethanol-type fermentation and results showed that ethanol-type fermentation was improved temporarily, however, was followed by the reappearance of butyrate-type fermentation. In addition, ethanol-type fermentation recovered once more when pH was reverted to 4.0. Therefore, the results of this study suggest that a process of dynamic, sequenced pH control with the order pH 4.0, 5.5 and 4.0 might be a feasible controlling strategy for continuous and stable ethanol-type fermentation. Copyright © 2016 Elsevier Ltd. All rights reserved.
Type-Based Access Control in Data-Centric Systems
NASA Astrophysics Data System (ADS)
Caires, Luís; Pérez, Jorge A.; Seco, João Costa; Vieira, Hugo Torres; Ferrão, Lúcio
Data-centric multi-user systems, such as web applications, require flexible yet fine-grained data security mechanisms. Such mechanisms are usually enforced by a specially crafted security layer, which adds extra complexity and often leads to error prone coding, easily causing severe security breaches. In this paper, we introduce a programming language approach for enforcing access control policies to data in data-centric programs by static typing. Our development is based on the general concept of refinement type, but extended so as to address realistic and challenging scenarios of permission-based data security, in which policies dynamically depend on the database state, and flexible combinations of column- and row-level protection of data are necessary. We state and prove soundness and safety of our type system, stating that well-typed programs never break the declared data access control policies.
2013-01-01
Background In the present study, we tested the hypothesis that carnitine supplementation counteracts obesity-induced muscle fiber transition from type I to type II. Methods 24 obese Zucker rats were randomly divided into two groups of 12 rats each (obese control, obese carnitine) and 12 lean Zucker rats were selected for lean control group. A control diet was given to both control groups and a carnitine supplemented diet (3 g/kg diet) was given to obese carnitine group for 4 wk. Components of the muscle fiber transformation in skeletal muscle were examined. Results The plasma level of carnitine were lower in the obese control group compared to the lean control group and higher in the obese carnitine group than in the other groups (P < 0.05). Plasma concentrations of triglycerides and non-esterified fatty acids were increased in obese animals compared to lean animals and the obese carnitine group had lower level compared to the obese control group (P < 0.05). The obese carnitine group had an increased number of type I muscle fibers and higher mRNA levels of type I fiber-specific myosin heavy chain, regulators of muscle fiber transition and of genes involved in carnitine uptake, fatty acid transport, β-oxidation, angiogenesis, tricarboxylic acid cycle and thermo genesis in M. rectus femoris compared to the other groups (P < 0.05). Conclusion The results demonstrate that carnitine supplementation to obese Zucker a rat counteracts the obesity-induced muscle fiber transition and restores the muscle oxidative metabolic phenotype. Carnitine supplementation is supposed to be beneficial for the treatment of elevated levels of plasma lipids during obesity or diabetes. PMID:23842456
Schechter, J; Green, L W; Olsen, L; Kruse, K; Cargo, M
1997-01-01
To apply Karasek's Job Content Model to an analysis of the relationships between job type and perceived stress and stress behaviors in a large company during a period of reorganization and downsizing. Cross-sectional mail-out, mail-back survey. A large Canadian telephone/telecommunications company. Stratified random sample (stratified by job category) of 2200 out of 13,000 employees with a response rate of 48.8%. Responses to 25 of Karasek's core questions were utilized to define four job types: low-demand and high control = "relaxed"; high demand and high control = "active"; low demand and low control = "passive", and high demand and low control = "high strain." These job types were compared against self-reported stress levels, perceived general level of health, absenteeism, alcohol use, exercise level, and use of medications and drugs. Similar analyses were performed to assess the influence of shift work. Employees with "passive" or "high strain" job types reported higher levels of stress (trend test p < .0001); poorer health (trend test P = .006); and higher levels of absenteeism (trend test p < .0001). More shift workers reported themselves in poor or fair health (chi-square p = .018) and reported high levels of stress at home (chi-square p = .002) than nonshift workers. The relationships between job type and levels of stress, health and absenteeism, however, held for nonshift workers as well. Job types with high demand and low control were associated with increased stress, increased absenteeism, and poorer self-concept of health. The demand/control model of Karasek and Theorell was validated in this setting with respect to stress and some stress-associated attitudes and behaviors.
Federal Register 2010, 2011, 2012, 2013, 2014
2013-01-11
... rulemaking. This document asks for responses to a series of questions regarding formats, types of material to... the types of material that could potentially be moved from the MUTCD to the Applications Supplement... seeks input on the type of material to be included in the MUTCD and the Applications Supplement, as well...
40 CFR Appendix B to Part 75 - Quality Assurance and Quality Control Procedures
Code of Federal Regulations, 2014 CFR
2014-07-01
... transmitters of an orifice-, nozzle-, or venturi-type fuel flowmeter under section 2.1.6 of appendix D to this... nozzle) of an orifice-, venturi-, or nozzle-type fuel flowmeter. Examples of the types of information to..., but ≤200 ppm). The out-of-control period begins upon failure of the calibration error test and ends...
Shi, Qifang; Ostwald, Sharon K; Wang, Shaopeng
2010-02-01
To examine the effect of a hospital-based clinic intervention on glycaemic control self-efficacy and glycaemic control behaviour of Chinese patients with type 2 diabetes mellitus (DM). Self-efficacy expectations are related to self-management of diabetes and, in conjunction with environmental support, are better predictors of behaviour than are knowledge and skills. Enhancing self-efficacy in patients with DM has been shown to have a positive effect on behavioural change and positively influence long-term glycaemic control. A randomised controlled trial study consisting of two-group pretest-post-test. One hundred and fifty-seven patients with type 2 DM were randomly divided into two groups: (1) the experimental group (77 patients) receiving one-month hospital-based clinic intervention and (2) the control group (80 patients) receiving usual care. Data collection instruments used in this study were Diabetes Management Self-Efficacy Scale and Summary of Diabetes Self-Care Activities Measure. Outcomes were determined by changes in glycaemic control self-efficacy and glycaemic control behaviour of patients with type 2 DM. The findings revealed that the experimental group showed statistically significant improvement in glycaemic control self-efficacy and glycaemic control behaviour immediately and four months after the intervention (F = 26.888, df = 1, 155, p < 0.05 and F = 18.619, df = 1, 155, p < 0.05, respectively). One-month hospital-based clinic intervention could be useful in improving glycaemic control self-efficacy and glycaemic control behaviour. Nurses can learn and use the sources of self-efficacy to enhance patients' self-efficacy on their glycaemic control in clinical care. The health education is most important in nursing care and should be considered while organising the hospital-based clinic intervention.
Amador-Angulo, Leticia; Mendoza, Olivia; Castro, Juan R.; Rodríguez-Díaz, Antonio; Melin, Patricia; Castillo, Oscar
2016-01-01
A hybrid approach composed by different types of fuzzy systems, such as the Type-1 Fuzzy Logic System (T1FLS), Interval Type-2 Fuzzy Logic System (IT2FLS) and Generalized Type-2 Fuzzy Logic System (GT2FLS) for the dynamic adaptation of the alpha and beta parameters of a Bee Colony Optimization (BCO) algorithm is presented. The objective of the work is to focus on the BCO technique to find the optimal distribution of the membership functions in the design of fuzzy controllers. We use BCO specifically for tuning membership functions of the fuzzy controller for trajectory stability in an autonomous mobile robot. We add two types of perturbations in the model for the Generalized Type-2 Fuzzy Logic System to better analyze its behavior under uncertainty and this shows better results when compared to the original BCO. We implemented various performance indices; ITAE, IAE, ISE, ITSE, RMSE and MSE to measure the performance of the controller. The experimental results show better performances using GT2FLS then by IT2FLS and T1FLS in the dynamic adaptation the parameters for the BCO algorithm. PMID:27618062
Iron-binding antioxidant capacity is impaired in diabetes mellitus.
Van Campenhout, Ann; Van Campenhout, Christel; Lagrou, Albert R; Moorkens, Greta; De Block, Christophe; Manuel-y-Keenoy, Begoña
2006-05-15
Increased lipid peroxidation contributes to diabetic complications and redox-active iron is known to play an important role in catalyzing peroxidation reactions. We aimed to investigate if diabetes affects the capacity of plasma to protect against iron-driven lipid peroxidation and to identify underlying factors. Glycemic control, serum iron, proteins involved in iron homeostasis, plasma iron-binding antioxidant capacity in a liposomal model, and non-transferrin-bound iron were measured in 40 type 1 and 67 type 2 diabetic patients compared to 100 nondiabetic healthy control subjects. Iron-binding antioxidant capacity was significantly lower in the plasma of diabetic subjects (83 +/- 6 and 84 +/- 5% in type 1 and type 2 diabetes versus 88 +/- 6% in control subjects, p < 0.0005). The contribution of transferrin, ceruloplasmin, and albumin concentrations to the iron-binding antioxidant capacity was lost in diabetes (explaining only 4.2 and 6.3% of the variance in type 1 and type 2 diabetes versus 13.9% in control subjects). This observation could not be explained by differences in Tf glycation, lipid, or inflammatory status and was not associated with higher non-transferrin-bound iron levels. Iron-binding antioxidant capacity is decreased in diabetes mellitus.
Lyapunov exponents and phase diagrams reveal multi-factorial control over TRAIL-induced apoptosis
Aldridge, Bree B; Gaudet, Suzanne; Lauffenburger, Douglas A; Sorger, Peter K
2011-01-01
Receptor-mediated apoptosis proceeds via two pathways: one requiring only a cascade of initiator and effector caspases (type I behavior) and the second requiring an initiator–effector caspase cascade and mitochondrial outer membrane permeabilization (type II behavior). Here, we investigate factors controlling type I versus II phenotypes by performing Lyapunov exponent analysis of an ODE-based model of cell death. The resulting phase diagrams predict that the ratio of XIAP to pro-caspase-3 concentrations plays a key regulatory role: type I behavior predominates when the ratio is low and type II behavior when the ratio is high. Cell-to-cell variability in phenotype is observed when the ratio is close to the type I versus II boundary. By positioning multiple tumor cell lines on the phase diagram we confirm these predictions. We also extend phase space analysis to mutations affecting the rate of caspase-3 ubiquitylation by XIAP, predicting and showing that such mutations abolish all-or-none control over activation of effector caspases. Thus, phase diagrams derived from Lyapunov exponent analysis represent a means to study multi-factorial control over a complex biochemical pathway. PMID:22108795
Samuelsson, Åsa; Houkes, Inge; Verdonk, Petra; Hammarström, Anne
2012-03-01
To investigate whether type of employment was related to work characteristics and health status at age 42 adjusted for health status at age 30 and whether gender moderates the associations. Questionnaire data was used from a 27-year follow-up study of school-leavers carried out in Luleå in the north of Sweden (response rate 94%). The study population consisted of 877 (47.8% women) working respondents. Data were analysed by means of t-tests, ANOVAs, and multiple linear regression analyses. Men were more often self-employed, while more women had temporary types of employment. Moreover, men reported more control over work and less emotional exhaustion than women. Compared to permanently employed, self-employed (men and women) perceived more control over work and better health status (p<0.01). Self-employed men also reported more demands and social support (p<0.05). People in temporary types of employment, however, reported less job control, as well as lower health status (only men) (p<0.01). Poor self-reported health and emotional exhaustion were significantly (p<0.05) associated with poor work characteristics (more demands, lower job control, and lower support). No direct associations between type of employment and health were found for women and men. However we find indications of an influence of type of employment on work and thereupon health, with job control playing an important role.
NASA Technical Reports Server (NTRS)
Monta, W. J.
1977-01-01
An experimental investigation was conducted on a model of a wing control version of the Sparrow III type missile to determine the static aerodynamic characteristics over an angle of attack range from 0 deg to 40 deg for Mach numbers from 1.50 to 4.60.
NASA Technical Reports Server (NTRS)
Chukwu, E. N.
1980-01-01
The problem of Lurie is posed for systems described by a functional differential equation of neutral type. Sufficient conditions are obtained for absolute stability for the controlled system if it is assumed that the uncontrolled plant equation is uniformly asymptotically stable. Both the direct and indirect control cases are treated.
Audio Control Handbook For Radio and Television Broadcasting. Third Revised Edition.
ERIC Educational Resources Information Center
Oringel, Robert S.
Audio control is the operation of all the types of sound equipment found in the studios and control rooms of a radio or television station. Written in a nontechnical style for beginners, the book explains thoroughly the operation of all types of audio equipment. Diagrams and photographs of commercial consoles, microphones, turntables, and tape…
Tavakol Moghadam, Salma; Najafi, Seyed Saeed; Yektatalab, Shahrzad
2018-01-01
The role of Emotional Intelligence (EI) in glycemic control in type 2 Diabetes Mellitus (DM) has not been fully understood. The present study aimed to investigate the effect of self-care education on EI and hemoglobin glycosylated (HbA1c) in patients with type 2 diabetes. In this randomized controlled clinical trial, 48 patients with type 2 DM referred to Shahid Motahari Diabetes Center in 2015 were divided into an intervention and a control group using block randomization. The study data were collected using Bar-On questionnaire and blood testing immediately and two months after the intervention. The educational content was presented to the intervention group through 1-1:30-hour sessions held once a week for 8 continuous weeks. The control group, however, only received the clinic's routine cares. The results showed a significant difference in the mean level of HbA1c in the intervention group before and two months after the intervention (P=0.003). However, this difference was not significant in the control group. Moreover, the mean of EI was higher in the intervention group compared to the control group (P=0.08). Self-care education improved the HbA1c level and EI among the patients with type 2 DM. Therefore, it is recommended that health care providers, specially nurses, should train the diabetic patients for self-care, which can lead to better glycemic control. Trial Registration Number: IRCT201408188505N7.
Type 2 Diabetes: Model of Factors Associated with Glycemic Control.
Aghili, Rokhsareh; Polonsky, William H; Valojerdi, Ameneh Ebrahim; Malek, Mojtaba; Keshtkar, Abbas Ali; Esteghamati, Alireza; Heyman, Mark; Khamseh, Mohammad Ebrahim
2016-10-01
The purpose of this study was to evaluate the related factors and their intercorrelated impacts on glycemic control in people with type 2 diabetes mellitus. Patients with type 2 diabetes were recruited for this study during their regular clinic visits at a major medical centre in Iran. Glycated hemoglobin (A1C) levels were used as the indicator of glycemic control. Regression analysis was used to determine the relationships between glycemic control and demographics, self-care behaviours, resources and affective variables. Moreover, the associations between diabetes-related distress and measured variables were tested. Three hundred eighty people with type 2 diabetes completed the study. The mean duration of diabetes was 8.94±6.57 years, and the mean A1C levels were 7.78%±1.7%. Diabetes-related distress was significantly associated with A1C levels, controlling for all other variables (p=0.01). On the other hand, depression (p<0.001), self-management (p<0.001), anxiety (p<0.001) and patient-physician relationship (p=0.023) were significantly associated with diabetes-related distress. Diabetes-related distress was found to be associated with glycemic control in people with type 2 diabetes, whereas age, depression, anxiety, self-management and family and social support may affect glycemic control indirectly through diabetes-related distress. Thus, it is important to assess and, if appropriate, treat people with diabetes for diabetes-related distress in order to identify and help them overcome barriers to optimal glycemic control. Copyright © 2016 Canadian Diabetes Association. All rights reserved.
Tavakol Moghadam, Salma; Najafi, Seyed Saeed; Yektatalab, Shahrzad
2018-01-01
ABSTRACT Background: The role of Emotional Intelligence (EI) in glycemic control in type 2 Diabetes Mellitus (DM) has not been fully understood. The present study aimed to investigate the effect of self-care education on EI and hemoglobin glycosylated (HbA1c) in patients with type 2 diabetes. Methods: In this randomized controlled clinical trial, 48 patients with type 2 DM referred to Shahid Motahari Diabetes Center in 2015 were divided into an intervention and a control group using block randomization. The study data were collected using Bar-On questionnaire and blood testing immediately and two months after the intervention. The educational content was presented to the intervention group through 1-1:30-hour sessions held once a week for 8 continuous weeks. The control group, however, only received the clinic’s routine cares. Results: The results showed a significant difference in the mean level of HbA1c in the intervention group before and two months after the intervention (P=0.003). However, this difference was not significant in the control group. Moreover, the mean of EI was higher in the intervention group compared to the control group (P=0.08). Conclusion: Self-care education improved the HbA1c level and EI among the patients with type 2 DM. Therefore, it is recommended that health care providers, specially nurses, should train the diabetic patients for self-care, which can lead to better glycemic control. Trial Registration Number: IRCT201408188505N7 PMID:29344534
USDA-ARS?s Scientific Manuscript database
Intensive lifestyle management or frequent goal-based monitoring with pharmacological management can be successful strategies for blood pressure control in overweight and obese adults with type 2 diabetes....
Control of Parts Shipped Prior to Type Certificate Issuance
DOT National Transportation Integrated Search
1991-10-21
This order prescribes the responsibilities and procedures for Federal Aviation Administration (FAA) Directorate personnel to review and evaluate proposals for control of parts shipped in advance of type certification of a new aircraft, aircraft engin...
David V. SANDBERG; Franklin R. Ward
1981-01-01
This publication presents tables on the behavior of fire and the resistance of fuels to control. The information is to be used with the photos in the publication, "Photo Series for Quantifying Forest Residues in the Coastal Douglas-firâHemlock Type, Coastal Douglas-firâHardwood Type" (Maxwell, Wayne G.; Ward, Franklin R. 1976. Gen. Tech. Rep. PNW-GTR-051....
Al-Attas, Safia A; Amro, Soliman O
2010-01-01
Candidal colonization in diabetics is a matter of debate. The aim of this study is to investigate oral candidal colonization, strain diversity, antifungal susceptibility, and the influence of local and systemic host factors on candidal colonization in adult diabetics. We conducted a case-control study that compared 150 diabetics (49 type 1, 101 type 2) with 50 healthy controls. Two salivary samples were collected, using the oral rinse sampling method: one for salivary flow rate and pH determination, and the other for candidal colonization assessment. The candidal isolates were identified and tested in vitro for antifungal susceptibility using the commercial kit, Candifast. The relationship between specific host factors and candidal colonization was also investigated. Diabetics had a higher candidal carriage rate compared to controls, but not density. Candida albicans was the most frequently isolated species, but diabetics had a variety of other candidal species present. None of the control samples were resistant to any tested antifungal, while the diabetic samples had differing resistances to azole antifungals. Although there was a significant positive correlation between glycemic control and candidal colonization in type 2 diabetics, there was a negative correlation between salivary pH and candidal carriage in the controls versus density in type 2 diabetics. Diabetic patients not only had a higher candidal carriage rate, but also a variety of candidal species that were resistant to azole antifungals. Oral candidal colonization was significantly associated with glycemic control, type of diabetes, and salivary pH.
RF kicker cavity to increase control in common transport lines
Douglas, David R.; Ament, Lucas J. P.
2017-04-18
A method of controlling e-beam transport where electron bunches with different characteristics travel through the same beam pipe. An RF kicker cavity is added at the beginning of the common transport pipe or at various locations along the common transport path to achieve independent control of different bunch types. RF energy is applied by the kicker cavity kicks some portion of the electron bunches, separating the bunches in phase space to allow independent control via optics, or separating bunches into different beam pipes. The RF kicker cavity is operated at a specific frequency to enable kicking of different types of bunches in different directions. The phase of the cavity is set such that the selected type of bunch passes through the cavity when the RF field is at a node, leaving that type of bunch unaffected. Beam optics may be added downstream of the kicker cavity to cause a further separation in phase space.
Glycemic control and high-density lipoprotein characteristics in adolescents with type 1 diabetes.
Medina-Bravo, Patricia; Medina-Urrutia, Aída; Juárez-Rojas, Juan Gabriel; Cardoso-Saldaña, Guillermo; Jorge-Galarza, Esteban; Posadas-Sánchez, Rosalinda; Coyote-Estrada, Ninel; Nishimura-Meguro, Elisa; Posadas-Romero, Carlos
2013-09-01
Recent evidence suggests that high-density lipoprotein (HDL) physicochemical characteristics and functional capacity may be more important that HDL-C levels in predicting coronary heart disease. There is little data regarding HDL subclasses distribution in youth with type 1 diabetes. To assess the relationships between glycemic control and HDL subclasses distribution, composition, and function in adolescents with type 1 diabetes. This cross-sectional study included 52 adolescents with type 1 diabetes aged 12-16 years and 43 age-matched non-diabetic controls. Patients were divided into two groups: one in fair control [hemoglobin A1c (HbA1c) < 9.6%] and the second group with poor glycemic control (HbA1c ≥ 9.6%). In all participants, we determined HDL subclasses distribution, composition, and the ability of plasma and of isolated HDL to promote cellular cholesterol efflux. Levels of soluble adhesion molecules were also measured. Although both groups of patients and the control group had similar HDL-C levels, linear regression analyses showed that compared with non-diabetic subjects, the poor control group had a lower proportion of HDL2b subclass (p = 0.029), triglyceride enriched (p = 0.045), and cholesteryl ester depleted (p = 0.028) HDL particles. Despite these HDL changes, cholesterol efflux was comparable among the three groups. The poor control group also had significantly higher intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 plasma concentrations. In adolescents with type 1 diabetes, poor glycemic control is associated with abnormalities in HDL subclasses distribution and HDL lipid composition, however, in spite of these HDL changes, the ability of HDL to promote cholesterol efflux remains comparable to that of healthy subjects. © 2012 John Wiley & Sons A/S.
Sensorless Load Torque Estimation and Passivity Based Control of Buck Converter Fed DC Motor
Kumar, S. Ganesh; Thilagar, S. Hosimin
2015-01-01
Passivity based control of DC motor in sensorless configuration is proposed in this paper. Exact tracking error dynamics passive output feedback control is used for stabilizing the speed of Buck converter fed DC motor under various load torques such as constant type, fan type, propeller type, and unknown load torques. Under load conditions, sensorless online algebraic approach is proposed, and it is compared with sensorless reduced order observer approach. The former produces better response in estimating the load torque. Sensitivity analysis is also performed to select the appropriate control variables. Simulation and experimental results fully confirm the superiority of the proposed approach suggested in this paper. PMID:25893208
Automating Access Control Logics in Simple Type Theory with LEO-II
NASA Astrophysics Data System (ADS)
Benzmüller, Christoph
Garg and Abadi recently proved that prominent access control logics can be translated in a sound and complete way into modal logic S4. We have previously outlined how normal multimodal logics, including monomodal logics K and S4, can be embedded in simple type theory and we have demonstrated that the higher-order theorem prover LEO-II can automate reasoning in and about them. In this paper we combine these results and describe a sound (and complete) embedding of different access control logics in simple type theory. Employing this framework we show that the off the shelf theorem prover LEO-II can be applied to automate reasoning in and about prominent access control logics.
Lind, T; Waernbaum, I; Berhan, Y; Dahlquist, G
2012-03-01
Mood disorders, including depression, are suggested to be prevalent in persons with type 1 diabetes and may negatively affect self-management and glycaemic control and increase the risk of diabetic complications. The aim of this study was to analyse the prevalence of antidepressant (AD) use in adults with childhood onset type 1 diabetes and to compare risk determinants for AD prescription among diabetic patients and a group of matched controls. Young adults ≥ 18 years on 1 January 2006 with type 1 diabetes (n = 7,411) were retrieved from the population-based Swedish Childhood Diabetes Registry (SCDR) and compared with 30,043 age- and community-matched controls. Individual level data were collected from the Swedish National Drug Register (NDR), the Hospital Discharge Register (HDR) and the Labor Market Research database (LMR). ADs were prescribed to 9.5% and 6.8% of the type 1 diabetes and control subjects, respectively. Female sex, having received economic or other social support, or having a disability pension were the factors with the strongest association with AD prescription in both groups. Type 1 diabetes was associated with a 44% (OR 1.44, 95% CI 1.32, 1.58) higher risk of being prescribed ADs in crude analysis. When adjusting for potential confounders including sex, age and various socioeconomic risk factors, this risk increase was statistically non-significant (OR 1.11, 95% CI 0.99, 1.21). The risk factor patterns for AD use are similar among type 1 diabetic patients and controls, and socioeconomic risk factors, rather than the diabetes per se, contribute to the increased risk of AD use in young adults with type 1 diabetes.
Banerji, Mary Ann; Dunn, Jeffrey D
2013-09-01
The incidence and prevalence of type 2 diabetes continue to grow in the United States and worldwide, along with the growing prevalence of obesity. Patients with type 2 diabetes are at greater risk for comorbid cardiovascular (CV) disease (CVD), which dramatically affects overall healthcare costs. To review the impact of glycemic control and medication adherence on morbidity, mortality, and healthcare costs of patients with type 2 diabetes, and to highlight the need for new drug therapies to improve outcomes in this patient population. This comprehensive literature search was conducted for the period between 2000 and 2013, using MEDLINE, to identify published articles that report the associations between glycemic control, medication adherence, CV morbidity and mortality, and healthcare utilization and costs. Search terms included "type 2 diabetes," "adherence," "compliance," "nonadherence," "drug therapy," "resource use," "cost," and "cost-effectiveness." Despite improvements in the management of CV risk factors in patients with type 2 diabetes, outcomes remain poor. The costs associated with the management of type 2 diabetes are increasing dramatically as the prevalence of the disease increases. Medication adherence to long-term drug therapy remains poor in patients with type 2 diabetes and contributes to poor glycemic control in this patient population, increased healthcare resource utilization and increased costs, as well as increased rates of comorbid CVD and mortality. Furthermore, poor adherence to established evidence-based guidelines for type 2 diabetes, including underdiagnosis and undertreatment, contributes to poor outcomes. New approaches to the treatment of patients with type 2 diabetes currently in development have the potential to improve medication adherence and consequently glycemic control, which in turn will help to reduce associated costs and healthcare utilization. As the prevalence of type 2 diabetes and its associated comorbidities grows, healthcare costs will continue to increase, indicating a need for better approaches to achieve glycemic control and manage comorbid conditions. Drug therapies are needed that enhance patient adherence and persistence levels far above levels reported with currently available drugs. Improvements in adherence to treatment guidelines and greater rates of lifestyle modifications also are needed. A serious unmet need exists for greatly improved patient outcomes, more effective and more tolerable drugs, as well as marked improvements in adherence to treatment guidelines and drug therapy to positively impact healthcare costs and resource use.
Theoretical characteristics in supersonic flow of two types of control surfaces on triangular wings
NASA Technical Reports Server (NTRS)
Tucker, Warren A; Nelson, Robert L
1949-01-01
Methods based on the linearized theory for supersonic flow were used to find the characteristics of two types of control surfaces on thin triangular wings. The first type, the constant-chord partial-span flap, was considered to extend either outboard from the center of the wing or inboard from the wing tip. The second type, the full-triangular-tip flap, was treated only for the case in which the Mach number component normal to the leading edge is supersonic. For each type, expressions were found for the lift, rolling-moment, pitching-moment, and hinge-moment characteristics.
Cheng, Shi-Hui; Ismail, Amin; Anthony, Joseph; Ng, Ooi Chuan; Hamid, Azizah Abdul; Barakatun-Nisak, Mohd Yusof
2015-01-01
Objectives. Optimizing glycemic control is crucial to prevent type 2 diabetes related complications. Cosmos caudatus is reported to have promising effect in improving plasma blood glucose in an animal model. However, its impact on human remains ambiguous. This study was carried out to evaluate the effectiveness of C. caudatus on glycemic status in patients with type 2 diabetes. Materials and Methods. In this randomized controlled trial with two-arm parallel-group design, a total of 101 subjects with type 2 diabetes were randomly allocated to diabetic-ulam or diabetic controls for eight weeks. Subjects in diabetic-ulam group consumed 15 g of C. caudatus daily for eight weeks while diabetic controls abstained from taking C. caudatus. Both groups received the standard lifestyle advice. Results. After 8 weeks of supplementation, C. caudatus significantly reduced serum insulin (−1.16 versus +3.91), reduced HOMA-IR (−1.09 versus +1.34), and increased QUICKI (+0.05 versus −0.03) in diabetic-ulam group compared with the diabetic controls. HbA1C level was improved although it is not statistically significant (−0.76% versus −0.37%). C. caudatus was safe to consume. Conclusions. C. caudatus supplementation significantly improves insulin resistance and insulin sensitivity in patients with type 2 diabetes. PMID:26713097
Genetic reinforcement learning through symbiotic evolution for fuzzy controller design.
Juang, C F; Lin, J Y; Lin, C T
2000-01-01
An efficient genetic reinforcement learning algorithm for designing fuzzy controllers is proposed in this paper. The genetic algorithm (GA) adopted in this paper is based upon symbiotic evolution which, when applied to fuzzy controller design, complements the local mapping property of a fuzzy rule. Using this Symbiotic-Evolution-based Fuzzy Controller (SEFC) design method, the number of control trials, as well as consumed CPU time, are considerably reduced when compared to traditional GA-based fuzzy controller design methods and other types of genetic reinforcement learning schemes. Moreover, unlike traditional fuzzy controllers, which partition the input space into a grid, SEFC partitions the input space in a flexible way, thus creating fewer fuzzy rules. In SEFC, different types of fuzzy rules whose consequent parts are singletons, fuzzy sets, or linear equations (TSK-type fuzzy rules) are allowed. Further, the free parameters (e.g., centers and widths of membership functions) and fuzzy rules are all tuned automatically. For the TSK-type fuzzy rule especially, which put the proposed learning algorithm in use, only the significant input variables are selected to participate in the consequent of a rule. The proposed SEFC design method has been applied to different simulated control problems, including the cart-pole balancing system, a magnetic levitation system, and a water bath temperature control system. The proposed SEFC has been verified to be efficient and superior from these control problems, and from comparisons with some traditional GA-based fuzzy systems.
Physical activity and electronic media use in the SEARCH for diabetes in youth case-control study.
Lobelo, Felipe; Liese, Angela D; Liu, Jihong; Mayer-Davis, Elizabeth J; D'Agostino, Ralph B; Pate, Russell R; Hamman, Richard F; Dabelea, Dana
2010-06-01
The aim of this study was to characterize the physical activity (PA) and electronic media (EM) use habits of a population-based, ascertained sample of youths with diabetes mellitus (DM). For this investigation, the Search for Diabetes in Youth Case-Control study (age: 10-20 y; 55% female) recruited 384 youths with provider-diagnosed type 1 DM, 90 youths with type 2 DM, and 173 healthy control subjects between 2003 and 2006, in 2 US centers. PA and EM use were assessed with a 3-day recall of activities, in 30-minute time blocks. Adherence to current recommendations was determined as a report of > or = 2 blocks of moderate/vigorous PA per day and <4 blocks of EM use per day. Differences in PA and EM use for DM/control groups were assessed with adjustment for age, study site, and race/ethnicity. Male subjects with type 2 DM reported lower levels of vigorous PA than did control subjects (1.1 vs 2.3 blocks; P < .05). Compliance with the moderate/vigorous PA recommendation among youths with type 2 DM was lower (68.3%), compared with youths with type 1 DM (81.7%; odds ratio: 0.51 [95% confidence interval: 0.26-1.00]; P = .047) and control subjects (80.4%; odds ratio: 0.48 [95% confidence interval: 0.23-1.02]; P = .05). Rates of compliance with EM use recommendations ranged from 29.5% to 49.1%. In this study, large proportions of youths with DM, especially type 2 DM, failed to meet PA and EM use recommendations.
Foran, E; Hannigan, A; Glynn, L
2015-06-01
As the Irish population ages, the management of chronic conditions in primary care is emerging as a challenge. The presence of co-morbid depression is common among such patients and may affect their response to treatment. This study sought to determine whether the prevalence of depression is higher in patients with type 2 diabetes mellitus than in the population aged >50 in the West of Ireland, and whether depression is an independent predictor of diabetes control. We used a cross-sectional design to examine an anonymized database of 9,698 patients aged >50 years whose medical data were collected as part of NUI Galway's CLARITY study. Glycosylated HbA1c levels were used to estimate type 2 DM control; depression was assessed using the Hospital Anxiety and Depression Scale. We found that while there is a higher prevalence of severe depression in patients with type 2 DM, there is no association between their diabetes control and depression after controlling for age, gender, comorbidity and GMS status. Multimorbidity is a significant predictor of depression in both diabetic and non-diabetic populations, with the odds of depression increasing as the number of co-morbidities increased. Patients with type 2 DM are more likely to suffer from severe depression than those without. Depression itself is not an independent predictor of diabetes control. However, it may be that the increased rates of depression observed in patients with type 2 DM are at least partially attributable to the burden of additional illnesses seen in these patients.
Nakanishi, Shuhei; Iwamoto, Masahiro; Kamei, Shinji; Hirukawa, Hidenori; Shimoda, Masashi; Tatsumi, Fuminori; Kohara, Kenji; Obata, Atsushi; Kimura, Tomohiko; Kinoshita, Tomoe; Irie, Shintaro; Sanada, Junpei; Fushimi, Yoshiro; Nishioka, Momoyo; Mizoguchi, Akiko; Kameyama, Miyuki; Mune, Tomoatsu; Kaku, Kohei; Kaneto, Hideaki
2018-01-01
Objective Insulin glargine [300 U/mL (Gla-300)] achieved better glycemic control and reduced the risk of hypoglycemia in comparison to glargine [100 U/mL; (Gla-100)] in phase 3 trials. This is the first study to retrospectively evaluate the efficacy and safety of Gla-300 in Japanese type 1 and 2 diabetes patients in a routine clinical setting. Methods We analyzed 20 type 1 diabetes patients and 62 type 2 diabetes patients who switched from Gla-100 to the same dose of Gla-300. Sixty type 2 diabetes patients who continued the use of Gla-100 during the study were included as controls. Results At three months after switching, the HbA1c levels were decreased in the patients with type 1 diabetes, but not to a significant extent. In the type 2 diabetes patients, the HbA1c levels were significantly decreased after switching (p<0.01). In contrast, there was no change in the HbA1c levels of the type 2 diabetes patients who continued the use of Gla-100 over the same period. The BMI values of the type 1 diabetes patients tended to decrease (p=0.06) and there was a significant decrease in the BMI values of the type 2 diabetes patients (p<0.05). There was no change in the BMI values of the type 2 diabetes patients who continued the use of Gla-100. The rates of hypoglycemia and adverse events did not change during the follow-up period. Conclusion In the clinical setting, switching from Gla-100 to the same dose of Gla-300 had a favorable effect on glycemic control and body weight control in Japanese type 1 and type 2 diabetes patients, without any increase in adverse events; however, a prospective study should be performed to confirm these findings.
Makhoul, Issam; Yacoub, Abdulraheem; Siegel, Eric
2016-01-01
The etiology of pancreatic cancer remains elusive. Several studies have suggested a role for diabetes mellitus, but the magnitude of its contribution remains controversial. Utilizing a large administrative database, this retrospective cohort study was designed to investigate the relationship between type 2 diabetes mellitus and pancreatic cancer. Using the Veterans Integrated Services Network 16 database, 322,614 subjects were enrolled in the study, including 110,919 with type 2 diabetes mellitus and 211,695 diabetes-free controls matched by gender, year of birth and healthcare facility. A significantly higher incidence of pancreatic cancer was observed in patients with type 2 diabetes mellitus, with an adjusted hazard ratio (95% confidence interval) of 2.17 (1.70-2.77) for type 2 diabetes mellitus compared to controls (p < 10 -9 ) after controlling for the matching factors. The association between type 2 diabetes mellitus and pancreatic cancer was statistically significant and may, in part, explain the rising incidence of pancreatic cancer.
Vannucci, Anna; Nelson, Eric E.; Bongiorno, Diana M.; Pine, Daniel S.; Yanovski, Jack A.; Tanofsky-Kraff, Marian
2015-01-01
Background Pediatric loss-of-control eating is a robust behavioral precursor to binge-type eating disorders. Elucidating precursors to loss-of-control eating and binge-type eating disorders may refine developmental risk models of eating disorders and inform interventions. Method We review evidence within constructs of the Negative Valence Systems (NVS)-domain, as specified by the Research Domain Criteria framework. Based on published studies, we propose an integrated NVS model of binge-type eating disorder risk. Results Data implicate altered corticolimbic functioning, neuroendocrine dysregulation, and self-reported negative affect as possible risk-factors. However, neuroimaging and physiological data in children and adolescents are sparse, and most prospective studies are limited to self-report measures. Conclusions We discuss a broad NVS framework for conceptualizing early risk for binge-type eating disorders. Future neural and behavioral research on the developmental trajectory of loss-of-control and binge-type eating disorders is required. PMID:26040923
SCF(KMD) controls cytokinin signaling by regulating the degradation of type-B response regulators.
Kim, Hyo Jung; Chiang, Yi-Hsuan; Kieber, Joseph J; Schaller, G Eric
2013-06-11
Cytokinins are plant hormones that play critical roles in growth and development. In Arabidopsis, the transcriptional response to cytokinin is regulated by action of type-B Arabidopsis response regulators (ARRs). Although central elements in the cytokinin signal transduction pathway have been identified, mechanisms controlling output remain to be elucidated. Here we demonstrate that a family of F-box proteins, called the kiss me deadly (KMD) family, targets type-B ARR proteins for degradation. KMD proteins form an S-phase kinase-associated PROTEIN1 (SKP1)/Cullin/F-box protein (SCF) E3 ubiquitin ligase complex and directly interact with type-B ARR proteins. Loss-of-function KMD mutants stabilize type-B ARRs and exhibit an enhanced cytokinin response. In contrast, plants with elevated KMD expression destabilize type-B ARR proteins leading to cytokinin insensitivity. Our results support a model in which an SCF(KMD) complex negatively regulates cytokinin responses by controlling levels of a key family of transcription factors.
Dissociating proportion congruent and conflict adaptation effects in a Simon-Stroop procedure.
Torres-Quesada, Maryem; Funes, Maria Jesús; Lupiáñez, Juan
2013-02-01
Proportion congruent and conflict adaptation are two well known effects associated with cognitive control. A critical open question is whether they reflect the same or separate cognitive control mechanisms. In this experiment, in a training phase we introduced a proportion congruency manipulation for one conflict type (i.e. Simon), whereas in pre-training and post-training phases two conflict types (e.g. Simon and Spatial Stroop) were displayed with the same incongruent-to-congruent ratio. The results supported the sustained nature of the proportion congruent effect, as it transferred from the training to the post-training phase. Furthermore, this transfer generalized to both conflict types. By contrast, the conflict adaptation effect was specific to conflict type, as it was only observed when the same conflict type (either Simon or Stroop) was presented on two consecutive trials (no effect was observed on conflict type alternation trials). Results are interpreted as supporting the reactive and proactive control mechanisms distinction. Copyright © 2013 Elsevier B.V. All rights reserved.
Yamaguchi, Motonori; Crump, Matthew J C; Logan, Gordon D
2013-06-01
Typing performance involves hierarchically structured control systems: At the higher level, an outer loop generates a word or a series of words to be typed; at the lower level, an inner loop activates the keystrokes comprising the word in parallel and executes them in the correct order. The present experiments examined contributions of the outer- and inner-loop processes to the control of speed and accuracy in typewriting. Experiments 1 and 2 involved discontinuous typing of single words, and Experiments 3 and 4 involved continuous typing of paragraphs. Across experiments, typists were able to trade speed for accuracy but were unable to type at rates faster than 100 ms/keystroke, implying limits to the flexibility of the underlying processes. The analyses of the component latencies and errors indicated that the majority of the trade-offs were due to inner-loop processing. The contribution of outer-loop processing to the trade-offs was small, but it resulted in large costs in error rate. Implications for strategic control of automatic processes are discussed. (PsycINFO Database Record (c) 2013 APA, all rights reserved).
Serum Progranulin Levels in Type 2 Diabetic Patients with Metabolic Syndrome.
Shafaei, Azam; Marjani, Abdoljalal; Khoshnia, Masoud
2016-12-01
The role of progranulin in individuals with metabolic syndrome is not exactly clear.We aimed to assess the serum level of progranulin in type 2 diabetic patients with and without metabolic syndrome and compare them with healthy controls. The study included 60 patients with type 2 diabetes and 30 healthy individuals as control groups. Biochemical parameters and progranulin levels were determined. Subjects with metabolic syndrome showed significantly higher levels of triglyceride, waist circumference, BMI, systolic and diastolic blood pressure than subjects without metabolic syndrome and the control groups, while HDL-cholesterol level was significantly lower in subjects with metabolic syndrome. Fasting blood sugar was significantly higher in type 2 diabetic patients than in the control groups. Serum level of progranulin was slightly increased in subjects with metabolic syndrome. Serum progranulin level had no significant relationship with metabolic syndrome components. Serum progranulin was also not dependent on cardiometabolic risk factors for subjects with metabolic syndrome, but it could be considered for the management of type 2 diabetes mellitus. Further studies are recommended to explain the effect of progranulin on the pathogenesis of metabolic risk factors.
Quality Control for Scoring Tests Administered in Continuous Mode: An NCME Instructional Module
ERIC Educational Resources Information Center
Allalouf, Avi; Gutentag, Tony; Baumer, Michal
2017-01-01
Quality control (QC) in testing is paramount. QC procedures for tests can be divided into two types. The first type, one that has been well researched, is QC for tests administered to large population groups on few administration dates using a small set of test forms (e.g., large-scale assessment). The second type is QC for tests, usually…
Type 2 diabetes detection and management among insured adults.
Dall, Timothy M; Yang, Weyna; Halder, Pragna; Franz, Jerry; Byrne, Erin; Semilla, April P; Chakrabarti, Ritashree; Stuart, Bruce
2016-01-01
The Centers for Disease Control and Prevention estimates that 28.9 million adults had diabetes in 2012 in the US, though many patients are undiagnosed or not managing their condition. This study provides US national and state estimates of insured adults with type 2 diabetes who are diagnosed, receiving exams and medication, managing glycemic levels, with diabetes complications, and their health expenditures. Such information can be used for benchmarking and to identify gaps in diabetes detection and management. The study combines analysis of survey data with medical claims analysis for the commercially insured, Medicare, and Medicaid populations to estimate the number of adults with diagnosed type 2 diabetes and undiagnosed diabetes by insurance type, age, and sex. Medical claims analysis used the 2012 de-identified Normative Health Information database covering a nationally representative commercially insured population, the 2011 Medicare 5% Sample, and the 2008 Medicaid Mini-Max. Among insured adults in 2012, approximately 16.9 million had diagnosed type 2 diabetes, 1.45 million had diagnosed type 1 diabetes, and 6.9 million had undiagnosed diabetes. Of those with diagnosed type 2, approximately 13.0 million (77%) received diabetes medication-ranging from 70% in New Jersey to 82% in Utah. Suboptimal percentages had claims indicating recommended exams were performed. Of those receiving diabetes medication, 43% (5.6 million) had medical claims indicating poorly controlled diabetes-ranging from 29% with poor control in Minnesota and Iowa to 53% in Texas. Poor control was correlated with higher prevalence of neurological complications (+14%), renal complications (+14%), and peripheral vascular disease (+11%). Patients with poor control averaged $4,860 higher average annual health care expenditures-ranging from $6,680 for commercially insured patients to $4,360 for Medicaid and $3,430 for Medicare patients. This study highlights the large number of insured adults with undiagnosed type 2 diabetes by insurance type and state. Furthermore, this study sheds light on other gaps in diabetes care quality among patients with diagnosed diabetes and corresponding poorly controlled diabetes. These findings underscore the need for improvements in data collection and diabetes screening and management, along with policies that support these improvements.
Schwingshackl, Lukas; Chaimani, Anna; Hoffmann, Georg; Schwedhelm, Carolina; Boeing, Heiner
2017-03-20
Dietary advice is one of the cornerstones in the management of type 2 diabetes mellitus. The American Diabetes Association recommended a hypocaloric diet for overweight or obese adults with type 2 diabetes in order to induce weight loss. However, there is limited evidence on the optimal approaches to control hyperglycemia in type 2 diabetes patients. The aim of the present study is to assess the comparative efficacy of different dietary approaches on glycemic control and blood lipids in patients with type 2 diabetes mellitus in a systematic review including a standard pairwise and network meta-analysis of randomized trials. We will conduct searches in Cochrane Central Register of Controlled Trials (CENTRAL) on the Cochrane Library, PubMed (from 1966), and Google Scholar. Citations, abstracts, and relevant papers will be screened for eligibility by two reviewers independently. Randomized controlled trials (with a control group or randomized trials with at least two intervention groups) will be included if they meet the following criteria: (1) include type 2 diabetes mellitus, (2) include patients aged ≥18 years, (3) include dietary intervention (different type of diets: e.g., Mediterranean dietary pattern, low-carbohydrate diet, low-fat diet, vegetarian diet, high protein diet); either hypo, iso-caloric, or ad libitum diets, (4) minimum intervention period of 12 weeks. For each outcome measure of interest, random effects pairwise and network meta-analyses will be performed in order to determine the pooled relative effect of each intervention relative to every other intervention in terms of the post-intervention values (or mean differences between the changes from baseline value scores). Subgroup analyses are planned for study length, sample size, age, and sex. This systematic review will synthesize the available evidence on the comparative efficacy of different dietary approaches in the management of glycosylated hemoglobin (primary outcome), fasting glucose, and cardiovascular risk factors in type 2 diabetes mellitus patients. The results of the present network meta-analysis will influence evidence-based treatment decisions since it will be fundamental for based recommendations in the management of type 2 diabetes. PROSPERO 42016047464.
Xie, Y; Zhang, Y; Qin, W; Lu, S; Ni, C; Zhang, Q
2017-03-01
Increasing DTI studies have demonstrated that white matter microstructural abnormalities play an important role in type 2 diabetes mellitus-related cognitive impairment. In this study, the diffusional kurtosis imaging method was used to investigate WM microstructural alterations in patients with type 2 diabetes mellitus and to detect associations between diffusional kurtosis imaging metrics and clinical/cognitive measurements. Diffusional kurtosis imaging and cognitive assessments were performed on 58 patients with type 2 diabetes mellitus and 58 controls. Voxel-based intergroup comparisons of diffusional kurtosis imaging metrics were conducted, and ROI-based intergroup comparisons were further performed. Correlations between the diffusional kurtosis imaging metrics and cognitive/clinical measurements were assessed after controlling for age, sex, and education in both patients and controls. Altered diffusion metrics were observed in the corpus callosum, the bilateral frontal WM, the right superior temporal WM, the left external capsule, and the pons in patients with type 2 diabetes mellitus compared with controls. The splenium of the corpus callosum and the pons had abnormal kurtosis metrics in patients with type 2 diabetes mellitus. Additionally, altered diffusion metrics in the right prefrontal WM were significantly correlated with disease duration and attention task performance in patients with type 2 diabetes mellitus. With both conventional diffusion and additional kurtosis metrics, diffusional kurtosis imaging can provide additional information on WM microstructural abnormalities in patients with type 2 diabetes mellitus. Our results indicate that WM microstructural abnormalities occur before cognitive decline and may be used as neuroimaging markers for predicting the early cognitive impairment in patients with type 2 diabetes mellitus. © 2017 by American Journal of Neuroradiology.
Sakaguchi, M; Miyazawa, H; Inouye, S
2000-03-01
We recently found that four children who experienced systemic immediate-type reactions to varicella vaccine with gelatin had anti-gelatin IgE. We also found systemic non-immediate-type allergic reactions, which mainly consist of systemic cutaneous signs, appearing several hours or more after the vaccination. To investigate the relationship between immune responses to gelatin and non-immediate-type reactions to gelatin-containing varicella vaccines, we measured anti-gelatin IgE and IgG in the sera of the children with these allergic reactions. Serum samples were taken from 21 children who showed non-immediate-type reactions to varicella vaccines. As a positive control, serum samples were taken from 33 children who showed immediate-type reactions to varicella vaccine and had anti-gelatin IgE. As a negative control, serum samples were taken from 50 children who showed no reaction to the vaccine. We then examined anti-gelatin IgE and IgG in sera of the children. Of 21 children with non-immediate-type reactions, two (10%) had anti-gelatin IgE and six (29%) had anti-gelatin IgG. In the positive control group, all 33 children with immediate-type reactions had anti-gelatin IgG as well as IgE. In the negative control group, all 50 children who showed no allergic reaction to varicella vaccines had neither anti-gelatin IgE nor IgG. These results suggest that the possibility exists that some non-immediate-type reactions to varicella vaccine are caused by immune reactions to gelatin.
Bond Strength of Gold Alloys Laser Welded to Cobalt-Chromium Alloy
Watanabe, Ikuya; Wallace, Cameron
2008-01-01
The objective of this study was to investigate the joint properties between cast gold alloys and Co-Cr alloy laser-welded by Nd:YAG laser. Cast plates were fabricated from three types of gold alloys (Type IV, Type II and low-gold) and a Co-Cr alloy. Each gold alloy was laser-welded to Co-Cr using a dental laser-welding machine. Homogeneously-welded and non-welded control specimens were also prepared. Tensile testing was conducted and data were statistically analyzed using ANOVA. The homogeneously-welded groups showed inferior fracture load compared to corresponding control groups, except for Co-Cr. In the specimens welded heterogeneously to Co-Cr, Type IV was the greatest, followed by low-gold and Type II. There was no statistical difference (P<0.05) in fracture load between Type II control and that welded to Co-Cr. Higher elongations were obtained for Type II in all conditions, whereas the lowest elongation occurred for low-gold welded to Co-Cr. This study indicated that, of the three gold alloys tested, the Type IV gold alloy was the most suitable alloy for laser-welding to Co-Cr. PMID:19088892
Kekäläinen, Päivi; Tirkkonen, Hilkka; Laatikainen, Tiina
2016-05-01
We assessed the prevalence of Type 1 diabetes mellitus and determined how the targets established in the guidelines for patients with Type 1 diabetes mellitus were achieved in clinical practice in North Karelia, Finland. All adult Type 1 diabetes mellitus patients (n=1075) were identified from the regional electronic patient database. The data for HbA1c and LDL cholesterol measurements during the years 2013 and 2014 were obtained from medical records. The prevalence of Type 1 diabetes mellitus in the adult population in North Karelia was 0.8%, which is among the highest worldwide. HbA1c and LDL cholesterol were measured in 93% and 90% of participants, respectively. Nineteen percent of patients reached the HbA1c target of <7.0% (53mmol/mol) and 45% attained LDL cholesterol <2.5mmol/l. Overall, 26% of patients over 60 years old with diabetes achieved glycaemic control targets compared with 13-16% of younger patients with diabetes. Glycaemic control was in line with the recommendations in only one-fifth of Type 1 diabetes mellitus patients and less than half of them had LDL cholesterol levels within the target range. Interestingly, older Type 1 diabetes mellitus patients met the glycaemic control target more often than younger patients with diabetes. The targets established for patients with Type 1 diabetes mellitus are not achieved satisfactorily in daily practice. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
[Skin graft, smoking and diabetes mellitus type 2].
Pérez-Guisado, Joaquín; Fidalgo-Rodríguez, Félix T; Gaston, Kate L; Rioja, Luis F; Thomas, Steven J
2012-01-01
Smoking and hyperglycemia decrease the success of skin graft survival in specific circumstances. It is well known that smoking and diabetes mellitus (DM) type 2 increase the oxidative and impair the endothelial function. The objective of this retrospective study was to determine if smoking and DM type 2 are factors associated with lower skin graft survival, in different etiologies of the injury associated to the skin loss. It was a bicentric, retrospective, cross sectional case control study, carried out on 2457 medical patients who met the inclusion criteria. It was carried out over a 10 years period between January 2000-December 2009, at Reina Sofía University Hospital (Córdoba, Spain) and UAB Hospital at Birmingham (Alabama, USA). The percentage of successful graft for each group and its control were analyzed by Chi-square test. The confidence interval chosen for statistical differences was 95%. Smoking and DM type 2 decreased the percentage of skin graft survival when compared with their control groups. DM type 2 was associated with greater negative success on skin graft survival than smoking when compared with their control groups. There was a statistically significant drop in skin graft of 18% in smoking group (range: 68-86%) and 25% in DM type 2 group (53-78%). The OR showed a clear association between the risk factors studied and the lower skin graft success, being stronger for DM type 2. In conclusion, DM type 2 and smoking are factors associated to lower skin graft take.
Influence of Nitroglycerin on Coronary Artery CT Imaging in Cardiovascular Diseases.
Zhang, PeiYing
2015-06-01
This study was designed to observe the influence of nitroglycerin on the quality of coronary artery imaging when CT is used for coronary heart disease. Data of 150 cardiology inpatients were collected from Department of Cardiology of our hospital from November 2013 to August 2014 for this study. All the subjects were diagnosed with multislice CT and coronary angiography after admission. The patients were then divided into two groups, the nitroglycerin group of 75 cases who took nitroglycerin and the control group of 75 cases who took no nitroglycerin. A total of 320 mixed plaques (pathological characteristics of calcified ingredients and non-calcified ingredients), including 290 calcified mixed plaques of type I, (mainly with calcified plaques and purely calcified plaques), and 30 non-calcified plaques of type II, (mainly with non-calcified ingredients or pure non-calcified plaques) were scanned. CT coronary angiography showed that the detection rate of type I plaque was 65.5 % in control group and 34.8 % in nitroglycerin group, whereas the detection rate of type II plaque was 30 % in control group and 70 % in nitroglycerin group. The difference for both type I and type II was statistically significant (p < 0.05). In Comparison with control group, the increase in diameter of 1-13 vascular segments in nitroglycerin group was statistically significant (p < 0.05). Taking nitroglycerin can improve the display resolution of coronary angiography, and shows better display for type I than type II plaques.
Simultaneous Control of Error Rates in fMRI Data Analysis
Kang, Hakmook; Blume, Jeffrey; Ombao, Hernando; Badre, David
2015-01-01
The key idea of statistical hypothesis testing is to fix, and thereby control, the Type I error (false positive) rate across samples of any size. Multiple comparisons inflate the global (family-wise) Type I error rate and the traditional solution to maintaining control of the error rate is to increase the local (comparison-wise) Type II error (false negative) rates. However, in the analysis of human brain imaging data, the number of comparisons is so large that this solution breaks down: the local Type II error rate ends up being so large that scientifically meaningful analysis is precluded. Here we propose a novel solution to this problem: allow the Type I error rate to converge to zero along with the Type II error rate. It works because when the Type I error rate per comparison is very small, the accumulation (or global) Type I error rate is also small. This solution is achieved by employing the Likelihood paradigm, which uses likelihood ratios to measure the strength of evidence on a voxel-by-voxel basis. In this paper, we provide theoretical and empirical justification for a likelihood approach to the analysis of human brain imaging data. In addition, we present extensive simulations that show the likelihood approach is viable, leading to ‘cleaner’ looking brain maps and operationally superiority (lower average error rate). Finally, we include a case study on cognitive control related activation in the prefrontal cortex of the human brain. PMID:26272730
Ma, Jianping; Wang, Jufang; Liu, Yanfen; Wang, Changyi; Duan, Donghui; Lu, Nanjia; Wang, Kaiyue; Zhang, Lu; Gu, Kaibo; Chen, Sihan; Zhang, Tao; You, Dingyun; Han, Liyuan
2017-02-01
The aim of this study was to compare the expression levels of serum miRNAs in diabetic retinopathy and type 2 diabetes mellitus. Serum miRNA expression profiles from diabetic retinopathy cases (type 2 diabetes mellitus patients with diabetic retinopathy) and type 2 diabetes mellitus controls (type 2 diabetes mellitus patients without diabetic retinopathy) were examined by miRNA-specific microarray analysis. Quantitative real-time polymerase chain reaction was used to validate the significantly differentially expressed serum miRNAs from the microarray analysis of 45 diabetic retinopathy cases and 45 age-, sex-, body mass index- and duration-of-diabetes-matched type 2 diabetes mellitus controls. The relative changes in serum miRNA expression levels were analyzed using the 2-ΔΔCt method. A total of 5 diabetic retinopathy cases and 5 type 2 diabetes mellitus controls were included in the miRNA-specific microarray analysis. The serum levels of miR-3939 and miR-1910-3p differed significantly between the two groups in the screening stage; however, quantitative real-time polymerase chain reaction did not reveal significant differences in miRNA expression for 45 diabetic retinopathy cases and their matched type 2 diabetes mellitus controls. Our findings indicate that miR-3939 and miR-1910-3p may not play important roles in the development of diabetic retinopathy; however, studies with a larger sample size are needed to confirm our findings.
Bernardi, Maria José; Reis, Alessandra; Loguercio, Alessandro Dourado; Kehrig, Ruth; Leite, Mariana Ferreira; Nicolau, José
2007-01-01
This study measured the flow rate, pH and buffering capacity of saliva from well- and poorly metabolically controlled Type 2 diabetic patients in three cities of the southern part of Brazil, compared with healthy individuals from the same cities. Whole saliva was collected by mechanical stimulation and buffering capacity and glucose level were measured. Blood was collected after 12 hours fasting and glucose and glycosylated haemoglobin concentrations were determined. The data were analysed by one-way ANOVA and Student-Newman-Keuls (alpha= 0.05). The flow rate was lower in the Type 2 diabetic patients, regardless of whether they were well or poorly metabolically controlled, compared with healthy individuals (p < 0.05). Salivary glucose concentration was higher in both diabetic patient groups, i.e. well and poorly metabolically controlled, than in the control (p < 0.05). The metabolic control of hyperglycaemia was not sufficient to improve the salivary flow rate or the salivary glucose concentration.
Kee, Dohyung
2002-01-01
The purpose of this study was to develop a new method for analytically generating three-dimensional isocomfort workspace for the upper extremities using the robot kinematics. Subjective perceived discomfort scores in varying postures for manipulating four types of controls were used. Fifteen healthy male subjects participated in the experiment. The subjects were asked to hold the given postures manipulating controls for 60 s in the seated position, and to rate their perceived discomfort during the following rest of 60 s using the magnitude estimation. Postures of the upper extremities set by shoulder and elbow motions, types of controls, and left right hand were selected as experimental variables, in which the L32 orthogonal array was adopted. The results showed that shoulder flexion and adduction-abduction, elbow flexion, and types of controls significantly affected perceived discomfort for postures operating controls, but hand used for operating controls did not. Depending upon the types of controls, four regression models predicting perceived discomfort were presented. Using the models, a sweeping algorithm to generate three-dimensional isocomfort workspace was developed, in which the robot kinematics was employed to describe the translational relationships between the upper arm and the lower arm/hand. It is expected that the isocomfort workspace can be used as a valuable design guideline when ergonomically designing three-dimensional workplaces.
Type 1 diabetes mellitus and risk of incident epilepsy: a population-based, open-cohort study.
Dafoulas, George E; Toulis, Konstantinos A; Mccorry, Dougall; Kumarendran, Balachadran; Thomas, G Neil; Willis, Brian H; Gokhale, Krishna; Gkoutos, George; Narendran, Parth; Nirantharakumar, Krishnarajah
2017-02-01
The aim of this research was to explore the relationship between incident epilepsy and type 1 diabetes in British participants. Using The Health Improvement Network database, we conducted a retrospective, open-cohort study. Patients who were newly diagnosed with type 1 diabetes mellitus at the age of ≤40 years were identified and followed-up from 1 January 1990 to 15 September 2015. These patients, identified as not suffering from epilepsy at the time of diagnosis, were randomly matched with up to four individuals without type 1 diabetes mellitus, based on age, sex and participating general practice. A Cox regression analysis was subsequently performed using Townsend deprivation index, cerebral palsy, head injury and learning disabilities as model covariates. The study population consisted of a total of 24,610 individuals (4922 with type 1 diabetes and 19,688 controls). These individuals were followed up for a mean of 5.4 years (approximately 132,000 person-years of follow up). Patients with type 1 diabetes were significantly more likely to be diagnosed with epilepsy during the observation period compared with controls (crude HR [95% CI]: 3.02 [1.95, 4.69]). The incidence rate was estimated to be 132 and 44 per 100,000 person-years in patients and controls, respectively. This finding persisted after adjusting for model covariates (adjusted HR [95% CI]: 3.01 [1.93, 4.68]) and was also robust to sensitivity analysis, excluding adult-onset type 1 diabetes mellitus. Patients with type 1 diabetes are at approximately three-times greater risk of developing epilepsy compared with matched controls without type 1 diabetes. This should be considered when investigating seizure-related disorders in patients with type 1 diabetes mellitus.
Douam, Florian; Soto Albrecht, Yentli E.; Hrebikova, Gabriela; Sadimin, Evita; Davidson, Christian; Kotenko, Sergei V.
2017-01-01
ABSTRACT Yellow fever virus (YFV) is an arthropod-borne flavivirus, infecting ~200,000 people worldwide annually and causing about 30,000 deaths. The live attenuated vaccine strain, YFV-17D, has significantly contributed in controlling the global burden of yellow fever worldwide. However, the viral and host contributions to YFV-17D attenuation remain elusive. Type I interferon (IFN-α/β) signaling and type II interferon (IFN-γ) signaling have been shown to be mutually supportive in controlling YFV-17D infection despite distinct mechanisms of action in viral infection. However, it remains unclear how type III IFN (IFN-λ) integrates into this antiviral system. Here, we report that while wild-type (WT) and IFN-λ receptor knockout (λR−/−) mice were largely resistant to YFV-17D, deficiency in type I IFN signaling resulted in robust infection. Although IFN-α/β receptor knockout (α/βR−/−) mice survived the infection, mice with combined deficiencies in both type I signaling and type III IFN signaling were hypersusceptible to YFV-17D and succumbed to the infection. Mortality was associated with viral neuroinvasion and increased permeability of the blood-brain barrier (BBB). α/βR−/− λR−/− mice also exhibited distinct changes in the frequencies of multiple immune cell lineages, impaired T-cell activation, and severe perturbation of the proinflammatory cytokine balance. Taken together, our data highlight that type III IFN has critical immunomodulatory and neuroprotective functions that prevent viral neuroinvasion during active YFV-17D replication. Type III IFN thus likely represents a safeguard mechanism crucial for controlling YFV-17D infection and contributing to shaping vaccine immunogenicity. PMID:28811340
USDA-ARS?s Scientific Manuscript database
Brazilian pepper is a weed in Florida, California and Hawaii that originates from South America. In Florida we have found two distinct types of Brazilian pepper plant and a hybrid between these two types. To control this weed, three biological control agents are being evaluated from Brazil. These ar...
Robustness of controllers designed using Galerkin type approximations
NASA Technical Reports Server (NTRS)
Morris, K. A.
1990-01-01
One of the difficulties in designing controllers for infinite-dimensional systems arises from attempting to calculate a state for the system. It is shown that Galerkin type approximations can be used to design controllers which will perform as designed when implemented on the original infinite-dimensional system. No assumptions, other than those typically employed in numerical analysis, are made on the approximating scheme.
An overview on STEP-NC compliant controller development
NASA Astrophysics Data System (ADS)
Othman, M. A.; Minhat, M.; Jamaludin, Z.
2017-10-01
The capabilities of conventional Computer Numerical Control (CNC) machine tools as termination organiser to fabricate high-quality parts promptly, economically and precisely are undeniable. To date, most CNCs follow the programming standard of ISO 6983, also called G & M code. However, in fluctuating shop floor environment, flexibility and interoperability of current CNC system to react dynamically and adaptively are believed still limited. This outdated programming language does not explicitly relate to each other to have control of arbitrary locations other than the motion of the block-by-block. To address this limitation, new standard known as STEP-NC was developed in late 1990s and is formalized as an ISO 14649. It adds intelligence to the CNC in term of interoperability, flexibility, adaptability and openness. This paper presents an overview of the research work that have been done in developing a STEP-NC controller standard and the capabilities of STEP-NC to overcome modern manufacturing demands. Reviews stated that most existing STEP-NC controller prototypes are based on type 1 and type 2 implementation levels. There are still lack of effort being done to develop type 3 and type 4 STEP-NC compliant controller.
Origin of negative resistance in anion migration controlled resistive memory
NASA Astrophysics Data System (ADS)
Banerjee, Writam; Wu, Facai; Hu, Yuan; Wu, Quantan; Wu, Zuheng; Liu, Qi; Liu, Ming
2018-03-01
Resistive random access memory (RRAM) is one of the most promising emerging nonvolatile technologies for the futuristic memory devices. Resistive switching behavior often shows negative resistance (NR), either voltage controlled or current controlled. In this work, the origin of a current compliance dependent voltage controlled NR effect during the resetting of anion migration based RRAM devices is discussed. The N-type voltage controlled NR is a high field driven phenomena. The current conduction within the range of a certain negative voltage is mostly dominated by space charge limited current. But with the higher negative voltage, a field induced tunneling effect is generated in the NR region. The voltage controlled NR is strongly dependent on the compliance current. The area independent behavior indicates the filamentary switching. The peak to valley ratio (PVR) is > 5. The variation of PVR as a function of the conduction band offset is achieved. Compared to other reported works, based on the PVR, it is possible to distinguish the RRAM types. Generally, due to the higher electric field effect on the metallic bridge during RESET, the electrochemical metallization type RRAM shows much higher PVR than the valance change type RRAM.
Cichosz, S L; Fleischer, J; Hoeyem, P; Laugesen, E; Poulsen, P L; Christiansen, J S; Ejskjær, N; Hansen, T K
2013-09-01
To evaluate physical activity in people with newly diagnosed Type 2 diabetes using objective measures. We analysed data from a study aimed at assessing carotid femoral pulse wave velocity in which a piezoelectric accelerometer was worn by 100 people with newly diagnosed Type 2 diabetes and by 100 age- and sex-matched control subjects. Differences in physical activity patterns were investigated. Compared with the control group, the people with Type 2 diabetes spent significantly more time engaged in sedentary or lower level activities during the day, with a mean (sd) time of 926 (44) vs 898 (70) min, P < 0.001). This difference remained significant after correction for differences in BMI between the two groups. Using objective measurements, our findings demonstrate that people with newly diagnosed Type 2 diabetes have a more sedentary lifestyle compared with well-matched controls. © 2013 The Authors. Diabetic Medicine © 2013 Diabetes UK.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Evans, M.L.; Carroll, H.A.
1986-07-01
The handbook describes basic types of foams that may be used to control vapor hazards from spilled volatile chemicals. It provides a table to be used by spill-response personnel to choose an appropriate foam based on the type of chemical spill. Six general types of foams, surfactant (syndet) foams, aqueous film forming foams (AFFF), alcohol type or polar solvent type foams (ATF), and special foams such as Hazmat NF no. 1 which was developed especially for alkaline spills. The handbook provides the basis for spill responders to evaluate and select a foam for vapor control by using the test methodsmore » presented or by considering manufacturers specifications for foam-expansion ratios and quarter drainage times. The responder is encouraged to maximize the effectiveness of a foam by trying different nozzles, distances of applications, and thicknesses of the foam layers.« less
On the Origins and Control of Community Types in the Human Microbiome
Cao, Hong-Tai; Weiss, Scott T.; Liu, Yang-Yu
2016-01-01
Microbiome-based stratification of healthy individuals into compositional categories, referred to as “enterotypes” or “community types”, holds promise for drastically improving personalized medicine. Despite this potential, the existence of community types and the degree of their distinctness have been highly debated. Here we adopted a dynamic systems approach and found that heterogeneity in the interspecific interactions or the presence of strongly interacting species is sufficient to explain community types, independent of the topology of the underlying ecological network. By controlling the presence or absence of these strongly interacting species we can steer the microbial ecosystem to any desired community type. This open-loop control strategy still holds even when the community types are not distinct but appear as dense regions within a continuous gradient. This finding can be used to develop viable therapeutic strategies for shifting the microbial composition to a healthy configuration. PMID:26866806
Lipoprotein composition in HNF1A-MODY: differentiating between HNF1A-MODY and type 2 diabetes.
McDonald, Tim J; McEneny, Jane; Pearson, Ewan R; Thanabalasingham, Gaya; Szopa, Magdalena; Shields, Beverley M; Ellard, Sian; Owen, Katharine R; Malecki, Maciej T; Hattersley, Andrew T; Young, Ian S
2012-05-18
The young-onset diabetes seen in HNF1A-MODY is often misdiagnosed as Type 2 diabetes. Type 2 diabetes, unlike HNF1A-MODY, is associated with insulin resistance and a characteristic dyslipidaemia. We aimed to compare the lipid profiles in HNF1A-MODY, Type 2 diabetes and control subjects and to determine if lipids can be used to aid the differential diagnosis of diabetes sub-type. 1) 14 subjects in each group (HNF1A-MODY, Type 2 diabetes and controls) were matched for gender and BMI. Fasting lipid profiles and HDL lipid constituents were compared in the 3 groups. 2) HDL-cholesterol was assessed in a further 267 patients with HNF1A-MODY and 297 patients with a diagnosis of Type 2 diabetes to determine its discriminative value. 1) In HNF1A-MODY subjects, plasma-triglycerides were lower (1.36 vs. 1.93 mmol/l, p = 0.07) and plasma-HDL-cholesterol was higher than in subjects with Type 2 diabetes (1.47 vs. 1.15 mmol/l, p = 0.0008), but was similar to controls. Furthermore, in the isolated HDL; HDL-phospholipid and HDL-cholesterol ester content were higher in HNF1A-MODY, than in Type 2 diabetes (1.59 vs. 1.33 mmol/L, p = 0.04 and 1.10 vs. 0.83 mmol/L, p = 0.019, respectively), but were similar to controls (1.59 vs. 1.45 mmol/L, p = 0.35 and 1.10 vs. 1.21 mmol/L, p = 0.19, respectively). 2) A plasma-HDL-cholesterol > 1.12 mmol/L was 75% sensitive and 64% specific (ROC AUC = 0.76) at discriminating HNF1A-MODY from Type 2 diabetes. The plasma-lipid profiles of HNF1A-MODY and the lipid constituents of HDL are similar to non-diabetic controls. However, HDL-cholesterol was higher in HNF1A-MODY than in Type 2 diabetes and could be used as a biomarker to aid in the identification of patients with HNF1A-MODY. Copyright © 2012 Elsevier B.V. All rights reserved.
Preliminary study of urine metabolism in type two diabetic patients based on GC-MS
Zhang, Ning; Geng, Fang; Hu, Zhong-Hua; Liu, Bin; Wang, Ye-Qiu; Liu, Jun-Cen; Qi, Yong-Hua; Li, Li-Jing
2016-01-01
Objective: Comparative study of type 2 diabetes and healthy controls by metabolomics methods to explore the pathogenesis of Type II diabetes. Methods: Gas chromatography - mass spectrometry (GC-MS) with a variety of multivariate statistical analysis methods to the healthy control group 58 cases, 68 cases of Type II diabetes group were analyzed. Chromatographic conditions: DB-5MS column; the carrier gas He; flow rate of 1 mL·min-1, the injection volume 1 uL; split ratio is 100: 1. MS conditions: electron impact (EI) ion source, an auxiliary temperature of 280°C, the ion source 230°C, quadrupole 150°C; mass scan range 30~600 mAu. Results: Established analytical method based on urine metabolomics GC-MS of Type II diabetes, determine the urine succinic acid, L-leucine, L-isoleucine, tyrosine, slanine, acetoace acid, mannose, L-isoleucine, L-threonine, Phenylalanine, fructose, D-glucose, palmi acid, oleic acid and arachidonic acid were significantly were significantly changed. Conclusion: Based on metabolomics of GC-MS detection and analysis metabolites can be found differences between type 2 diabetes and healthy control group, PCA diagram can effectively distinguish Type II diabetes and healthy control group, with load diagrams and PLS-DA VIP value metabolite screening, the resulting differences in metabolic pathways involved metabolites, including amino acid metabolism, lipid metabolism, glucose metabolism and energy metabolism. PMID:27508010
Evaluation of life cycle impacts of intersection control type selection [final report].
DOT National Transportation Integrated Search
2016-05-05
The methodology provided in this report provides guidance for NCDOT conversions of twoway : stop controlled intersections to other intersection types to enhance the effective allocation of : public funds. The findings of this project have been inc...
Arms Control, Disarmament, and Peace Newsletters.
ERIC Educational Resources Information Center
Atkins, Stephen
1986-01-01
Considers the research value of four types of newsletters on arms control, disarmament, and peace: direct-action, informational, scholarly, and single-issue. An annotated list of 58 newsletters includes those considered most significant of their type and recommended for library collections. (EM)
Factorization and reduction methods for optimal control of distributed parameter systems
NASA Technical Reports Server (NTRS)
Burns, J. A.; Powers, R. K.
1985-01-01
A Chandrasekhar-type factorization method is applied to the linear-quadratic optimal control problem for distributed parameter systems. An aeroelastic control problem is used as a model example to demonstrate that if computationally efficient algorithms, such as those of Chandrasekhar-type, are combined with the special structure often available to a particular problem, then an abstract approximation theory developed for distributed parameter control theory becomes a viable method of solution. A numerical scheme based on averaging approximations is applied to hereditary control problems. Numerical examples are given.
Circulating betatrophin is elevated in patients with type 1 and type 2 diabetes.
Yamada, Hodaka; Saito, Tomoyuki; Aoki, Atsushi; Asano, Tomoko; Yoshida, Masashi; Ikoma, Aki; Kusaka, Ikuyo; Toyoshima, Hideo; Kakei, Masafumi; Ishikawa, San-E
2015-01-01
There is evidence that betatrophin, a hormone derived from adipose tissue and liver, affects the proliferation of pancreatic beta cells in mice. The aim of this study was to examine circulating betatrophin concentrations in Japanese healthy controls and patients with type 1 and type 2 diabetes. A total of 76 subjects (12 healthy controls, 34 type 1 diabetes, 30 type 2 diabetes) were enrolled in the study. Circulating betatrophin was measured with an ELISA kit and clinical parameters related to betatrophin were analyzed statistically. Circulating betatrophin (Log transformed) was significantly increased in patients with diabetes compared with healthy subjects (healthy controls, 2.29 ± 0.51; type 1 diabetes, 2.94 ± 0.44; type 2 diabetes, 3.17 ± 0.18; p<0.001, 4.1 to 5.4 times in pg/mL order). Age, HbA1c, fasting plasma glucose and Log triglyceride were strongly associated with Log betatrophin in all subjects (n=76) in correlation analysis. In type 1 diabetes, there was a correlation between Log betatrophin and Log CPR. These results provide the first evidence that circulating betatrophin is significantly elevated in Japanese patients with diabetes. The findings of this pilot study also suggest a possibility of association between the level of betatrophin and the levels of glucose and triglycerides.
Learning From Past Failures of Oral Insulin Trials.
Michels, Aaron W; Gottlieb, Peter A
2018-07-01
Very recently one of the largest type 1 diabetes prevention trials using daily administration of oral insulin or placebo was completed. After 9 years of study enrollment and follow-up, the randomized controlled trial failed to delay the onset of clinical type 1 diabetes, which was the primary end point. The unfortunate outcome follows the previous large-scale trial, the Diabetes Prevention Trial-Type 1 (DPT-1), which again failed to delay diabetes onset with oral insulin or low-dose subcutaneous insulin injections in a randomized controlled trial with relatives at risk for type 1 diabetes. These sobering results raise the important question, "Where does the type 1 diabetes prevention field move next?" In this Perspective, we advocate for a paradigm shift in which smaller mechanistic trials are conducted to define immune mechanisms and potentially identify treatment responders. The stage is set for these interventions in individuals at risk for type 1 diabetes as Type 1 Diabetes TrialNet has identified thousands of relatives with islet autoantibodies and general population screening for type 1 diabetes risk is under way. Mechanistic trials will allow for better trial design and patient selection based upon molecular markers prior to large randomized controlled trials, moving toward a personalized medicine approach for the prevention of type 1 diabetes. © 2018 by the American Diabetes Association.
Circadian Rest-Activity Rhythm in Pediatric Type 1 Narcolepsy.
Filardi, Marco; Pizza, Fabio; Bruni, Oliviero; Natale, Vincenzo; Plazzi, Giuseppe
2016-06-01
Pediatric type 1 narcolepsy is often challenging to diagnose and remains largely undiagnosed. Excessive daytime sleepiness, disrupted nocturnal sleep, and a peculiar phenotype of cataplexy are the prominent features. The knowledge available about the regulation of circadian rhythms in affected children is scarce. This study compared circadian rest-activity rhythm and actigraphic estimated sleep measures of children with type 1 narcolepsy versus healthy controls. Twenty-two drug-naïve type 1 narcolepsy children and 21 age- and sex- matched controls were monitored for seven days during the school week by actigraphy. Circadian activity rhythms were analyzed through functional linear modeling; nocturnal and diurnal sleep measures were estimated from activity using a validated algorithm. Children with type 1 narcolepsy presented an altered rest-activity rhythm characterized by enhanced motor activity throughout the night and blunted activity in the first afternoon. No difference was found between children with type 1 narcolepsy and controls in the timing of the circadian phase. Actigraphic sleep measures showed good discriminant capabilities in assessing type 1 narcolepsy nycthemeral disruption. Actigraphy reliably renders the nycthemeral disruption typical of narcolepsy type 1 in drug-naïve children with recent disease onset, indicating the sensibility of actigraphic assessment in the diagnostic work-up of childhood narcolepsy type 1. © 2016 Associated Professional Sleep Societies, LLC.
Multiple modes of a-type potassium current regulation.
Cai, Shi-Qing; Li, Wenchao; Sesti, Federico
2007-01-01
Voltage-dependent potassium (K+) channels (Kv) regulate cell excitability by controlling the movement of K+ ions across the membrane in response to changes in the cell voltage. The Kv family, which includes A-type channels, constitute the largest group of K+ channel genes within the superfamily of Na+, Ca2+ and K+ voltage-gated channels. The name "A-type" stems from the typical profile of these currents that results form the opposing effects of fast activation and inactivation. In neuronal cells, A-type currents (I(A)), determine the interval between two consecutive action potentials during repetitive firing. In cardiac muscle, A-type currents (I(to)), control the initial repolarization of the myocardium. Structurally, A-type channels are tetramers of alpha-subunits each containing six putative transmembrane domains including a voltage-sensor. A-type channels can be modulated by means of protein-protein interactions with so-called beta-subunits that control inactivation voltage sensitivity and other properties, and by post-transcriptional modifications such as phosphorylation or oxidation. Recently a new mode of A-type regulation has been discovered in the form of a class of hybrid beta-subunits that posses their own enzymatic activity. Here, we review the biophysical and physiological properties of these multiple modes of A-type channel regulation.
Yan, Song; Li, Yun
2014-02-15
Despite its great capability to detect rare variant associations, next-generation sequencing is still prohibitively expensive when applied to large samples. In case-control studies, it is thus appealing to sequence only a subset of cases to discover variants and genotype the identified variants in controls and the remaining cases under the reasonable assumption that causal variants are usually enriched among cases. However, this approach leads to inflated type-I error if analyzed naively for rare variant association. Several methods have been proposed in recent literature to control type-I error at the cost of either excluding some sequenced cases or correcting the genotypes of discovered rare variants. All of these approaches thus suffer from certain extent of information loss and thus are underpowered. We propose a novel method (BETASEQ), which corrects inflation of type-I error by supplementing pseudo-variants while keeps the original sequence and genotype data intact. Extensive simulations and real data analysis demonstrate that, in most practical situations, BETASEQ leads to higher testing powers than existing approaches with guaranteed (controlled or conservative) type-I error. BETASEQ and associated R files, including documentation, examples, are available at http://www.unc.edu/~yunmli/betaseq
Dermatoglyphic patterns in dementia of the Alzheimer type: a case-control study.
Berr, C; Okra-Podrabinek, N; Feteanu, D; Taurand, S; Hervy, M P; Forette, F; Piette, F; Sebag-Lanoe, R; Alperovitch, A
1992-10-01
The aim was to compare digital and palmar dermatoglyphics in subjects with dementia of Alzheimer type and in mentally healthy elderly controls. This design was a case-control study. The study was carried out in geriatric units and retirement communities in the Paris area. Cases were women with clinically diagnosed Alzheimer type dementia according to DSM III-R criteria (n = 82), mainly with late onset of the disease. Controls were women aged 85 years or older without cognitive deterioration (n = 76). Finger and palm prints obtained from both hands by the classical ink method were examined. Fingerprints were classified into four types of figures. On palms, palmar flexion creases, palmar axial triradii, true patterns of the hypothenar area, and main line terminations were described. Examinations were performed by two examiners blind to the subjects's diagnostic category. For the different patterns studied, no major differences between dementia patients and elderly controls were found. Nor was there evidence of high frequencies of features commonly observed in Down's syndrome (trisomy 21), which have previously, though sporadically, been reported. On one of the largest samples of Alzheimer dementia patients studied, and with evaluation blind to diagnosis, no evidence has been found that particular dermatoglyphic patterns occur like those observed in Down's syndrome, a disease which is related to dementia of the Alzheimer type.
Distinct Effects of Type I and III Interferons on Enteric Viruses
Peterson, Stefan T.
2018-01-01
Interferons (IFNs) are key host cytokines in the innate immune response to viral infection, and recent work has identified unique roles for IFN subtypes in regulating different aspects of infection. Currently emerging is a common theme that type III IFNs are critical in localized control of infection at mucosal barrier sites, while type I IFNs are important for broad systemic control of infections. The intestine is a particular site of interest for exploring these effects, as in addition to being the port of entry for a multitude of pathogens, it is a complex tissue with a variety of cell types as well as the presence of the intestinal microbiota. Here we focus on the roles of type I and III IFNs in control of enteric viruses, discussing what is known about signaling downstream from these cytokines, including induction of specific IFN-stimulated genes. We review viral strategies to evade IFN responses, effects of IFNs on the intestine, interactions between IFNs and the microbiota, and briefly discuss the role of IFNs in controlling viral infections at other barrier sites. Enhanced understanding of the coordinate roles of IFNs in control of viral infections may facilitate development of antiviral therapeutic strategies; here we highlight potential avenues for future exploration. PMID:29361691
Cognitive vision system for control of dexterous prosthetic hands: Experimental evaluation
2010-01-01
Background Dexterous prosthetic hands that were developed recently, such as SmartHand and i-LIMB, are highly sophisticated; they have individually controllable fingers and the thumb that is able to abduct/adduct. This flexibility allows implementation of many different grasping strategies, but also requires new control algorithms that can exploit the many degrees of freedom available. The current study presents and tests the operation of a new control method for dexterous prosthetic hands. Methods The central component of the proposed method is an autonomous controller comprising a vision system with rule-based reasoning mounted on a dexterous hand (CyberHand). The controller, termed cognitive vision system (CVS), mimics biological control and generates commands for prehension. The CVS was integrated into a hierarchical control structure: 1) the user triggers the system and controls the orientation of the hand; 2) a high-level controller automatically selects the grasp type and size; and 3) an embedded hand controller implements the selected grasp using closed-loop position/force control. The operation of the control system was tested in 13 healthy subjects who used Cyberhand, attached to the forearm, to grasp and transport 18 objects placed at two different distances. Results The system correctly estimated grasp type and size (nine commands in total) in about 84% of the trials. In an additional 6% of the trials, the grasp type and/or size were different from the optimal ones, but they were still good enough for the grasp to be successful. If the control task was simplified by decreasing the number of possible commands, the classification accuracy increased (e.g., 93% for guessing the grasp type only). Conclusions The original outcome of this research is a novel controller empowered by vision and reasoning and capable of high-level analysis (i.e., determining object properties) and autonomous decision making (i.e., selecting the grasp type and size). The automatic control eases the burden from the user and, as a result, the user can concentrate on what he/she does, not on how he/she should do it. The tests showed that the performance of the controller was satisfactory and that the users were able to operate the system with minimal prior training. PMID:20731834
NASA Astrophysics Data System (ADS)
Altin, Necmi
2018-05-01
An interval type-2 fuzzy logic controller-based maximum power point tracking algorithm and direct current-direct current (DC-DC) converter topology are proposed for photovoltaic (PV) systems. The proposed maximum power point tracking algorithm is designed based on an interval type-2 fuzzy logic controller that has an ability to handle uncertainties. The change in PV power and the change in PV voltage are determined as inputs of the proposed controller, while the change in duty cycle is determined as the output of the controller. Seven interval type-2 fuzzy sets are determined and used as membership functions for input and output variables. The quadratic boost converter provides high voltage step-up ability without any reduction in performance and stability of the system. The performance of the proposed system is validated through MATLAB/Simulink simulations. It is seen that the proposed system provides high maximum power point tracking speed and accuracy even for fast changing atmospheric conditions and high voltage step-up requirements.
Alloway, S C; Toth, E L; McCargar, L J
2001-01-01
The coexistence of type 1 diabetes mellitus and disordered eating is associated with poor metabolic control, poor adherence to diabetes treatment regimens, and increased risk of long-term diabetic complications. This study assessed whether a six-session group psychoeducation program would improve metabolic control, diabetes treatment adherence, eating disorder symptomatology, and general psychopathology in women with coexisting type 1 diabetes and subclinical disordered eating. Fourteen women were assigned to the treatment group (n=8) or wait-list control group (n=6). Measurements were taken at baseline, post-intervention, and one month post-intervention. There were no significant differences in how the treatment group and wait-list control group changed over time. Between the first and second measurements, both groups demonstrated significant improvements in depression and general emotional distress. The results suggest that a six-session group psychoeducation program is no more effective than a wait-list control group for treating subclinical disordered eating in women with type 1 diabetes. Further research is required to determine the most effective treatment for this population.
van Dijk, Jan-Willem; Eijsvogels, Thijs M; Nyakayiru, Jean; Schreuder, Tim H A; Hopman, Maria T; Thijssen, Dick H; van Loon, Luc J C
2016-07-01
Despite its general benefits for health, exercise complicates the maintenance of stable blood glucose concentrations in individuals with type 1 diabetes. The aim of the current study was to examine changes in food intake, insulin administration, and 24-h glycemic control in response to consecutive days with prolonged walking exercise (∼8h daily) in individuals with type 1 diabetes. Ten individuals with type 1 diabetes participating in the worlds' largest walking event were recruited for this observational study. Simultaneous measurements of 24-h glycemic control (continuous glucose monitoring), insulin administration and food intake were performed during a non-walking day (control) and during three subsequent days with prolonged walking exercise (daily distance 40 or 50km). Despite an increase in daily energy (31±18%; p<0.01) and carbohydrate (82±71g; p<0.01) intake during walking days, subjects lowered their insulin administration by 26±16% relative to the control day (p<0.01). Average 24-h blood glucose concentrations, the prevalence of hyperglycemia (blood glucose >10 mmol/L) and hypoglycemia (blood glucose <3.9mmol/L) did not differ between the control day and walking days (p>0.05 for all variables). The prolonged walking exercise was associated with a modest increase in glycemic variability compared with the control day (p<0.05). Prolonged walking exercise allows for profound reductions in daily insulin administration in persons with type 1 diabetes, despite large increments in energy and carbohydrate intake. When taking such adjustments into account, prolonged moderate-intensity exercise does not necessarily impair 24-h glycemic control. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Static Postural Control in Youth With Osteogenesis Imperfecta Type I.
Pouliot-Laforte, Annie; Lemay, Martin; Rauch, Frank; Veilleux, Louis-Nicolas
2017-10-01
To assess static postural control in eyes-open and eyes-closed conditions in individuals with osteogenesis imperfecta (OI) type I as compared with typically developing (TD) individuals and to explore the relation between postural control and lower limb muscle function. Cross-sectional study. Outpatient department of a pediatric orthopedic hospital. A convenience sample (N=38) of individuals with OI type I (n=22; mean age, 13.1y; range, 6-21y) and TD individuals (n=16; mean age, 13.1y; range, 6-20y) was selected. Participants were eligible if they were between 6 and 21 years and if they did not have any fracture or surgery in the lower limb in the 12 months before testing. Not applicable. Postural control was assessed through static balance tests and muscle function through mechanographic tests on a force platform. Selected postural parameters were path length, velocity, 90% confidence ellipse area, and the ellipse's length of the mediolateral and anteroposterior axes. Mechanographic parameters were peak force and peak power as measured using the multiple two-legged hopping and the single two-legged jump test, respectively. Individuals with OI type I had poorer postural control than did TD individuals as indicated by longer and faster displacements and a larger ellipse area. Muscle function was unrelated to postural control in the OI group. Removing visual information resulted in a larger increase in postural control parameters in the OI group than in the TD group. A proprioceptive deficit could explain poorer postural control in individuals with OI type I. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.
THE INFLUENCE OF EXTRINSIC REINFORCEMENT ON CHILDREN WITH HEAVY PRENATAL ALCOHOL EXPOSURE
Graham, Diana M.; Glass, Leila; Mattson, Sarah N.
2016-01-01
Background Prenatal alcohol exposure affects inhibitory control and other aspects of attention and executive function. However, the efficacy of extrinsic reinforcement on these behaviors has not been tested. Methods Alcohol-exposed children (AE; n=34), children with ADHD (ADHD; n=23), and controls (CON; n=31) completed a flanker task with four reward conditions (no reward, reward, reward+occasional response cost, equal probability of reward+response cost). Inhibitory control was tested in the no reward conditions using a 3(group) x 2(flanker type) ANCOVA. Response to reinforcement was tested using 3(group) x 4(reward condition) x 4(flanker type) ANCOVA. Response time (RT) and accuracy were tested independently. Results Groups did not differ on demographic variables. The flanker task was successful in taxing interference control, an aspect of executive attention (i.e., responses to incongruent stimuli were slower than to congruent stimuli) and the AE group demonstrated impaired executive control over the other groups. Overall, the AE group had significantly slower response times compared to the CON and ADHD groups, which did not differ. However, reinforcement improved RT in all groups. While occasional response cost had the greatest benefit in the CON group, the type of reinforcement did not differentially affect the AE and ADHD groups. Accuracy across reward conditions did not differ by group, but was dependent on flanker type and reward condition. Conclusions Alcohol-exposed children, but not children with ADHD, had impaired interference control in comparison to controls, supporting a differential neurobehavioral profile in these two groups. Both clinical groups were equally affected by introduction of reinforcement, although the type of reinforcement did not differentially affect performance as it did in the control group, suggesting that reward or response cost could be used interchangeably to result in the same benefit. PMID:26842253
Antidepressant medication use and glycaemic control in co-morbid type 2 diabetes and depression.
Brieler, Jay A; Lustman, Patrick J; Scherrer, Jeffrey F; Salas, Joanne; Schneider, F David
2016-02-01
Depression is prevalent in diabetes and is associated with increased risks of hyperglycaemia, morbidity and mortality. The effect of antidepressant medication (ADM) on glycaemic control is uncertain owing to a paucity of relevant data. We sought to determine whether the use of ADM is associated with glycaemic control in depressed patients with type 2 diabetes. A retrospective cohort study (n = 1399) was conducted using electronic medical record registry data of ambulatory primary care visits from 2008 to 2013. Depression and type 2 diabetes were identified from ICD-9-CM codes; ADM use was determined from prescription orders; and glycaemic control was determined from measures of glycated haemoglobin (A1c). Good glycaemic control was defined as A1c < 7.0% (53 mmol/mol). Generalized estimating equations were used to determine the effect of depression and ADM use on glycaemic control. Good glycaemic control was achieved by 50.9% of depressed subjects receiving ADM versus 34.6% of depressed subjects without ADM. After adjusting for covariates, depressed patients receiving ADM were twice as likely as those not receiving ADM to achieve good glycaemic control (odds ratio = 1.95; 95% confidence interval: 1.02-3.71). In this retrospective cohort study of a large sample of primary care patients with type 2 diabetes, ADM use was associated with improved glycaemic control. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Emotional processing and self-control in adolescents with type 1 diabetes.
Hughes, Amy E; Berg, Cynthia A; Wiebe, Deborah J
2012-09-01
This study examined whether emotional processing (understanding emotions), self-control (regulation of thoughts, emotions, and behavior), and their interaction predicted HbA1c for adolescents with type 1 diabetes over and above diabetes-specific constructs. Self-report measures of self-control, emotional processing, self-efficacy for diabetes management, diabetes-specific negative affect, and adherence, and HbA1c from medical records were obtained from 137 adolescents with type 1 diabetes (M age = 13.48 years). Emotional processing interacted with self-control to predict HbA1c, such that when adolescents had both low emotional processing and low self-control, HbA1c was poorest. Also, both high emotional processing and self-control buffered negative effects of low capacity in the other in relation to HbA1c. The interaction of emotional processing × self-control predicted HbA1c over diabetes-specific self-efficacy, negative affect, and adherence. These findings suggest the importance of emotional processing and self-control for health outcomes in adolescents with diabetes.
Emotional Processing and Self-Control in Adolescents With Type 1 Diabetes
Hughes, Amy E.; Wiebe, Deborah J.
2012-01-01
Objective This study examined whether emotional processing (understanding emotions), self-control (regulation of thoughts, emotions, and behavior), and their interaction predicted HbA1c for adolescents with type 1 diabetes over and above diabetes-specific constructs. Methods Self-report measures of self-control, emotional processing, self-efficacy for diabetes management, diabetes-specific negative affect, and adherence, and HbA1c from medical records were obtained from 137 adolescents with type 1 diabetes (M age = 13.48 years). Results Emotional processing interacted with self-control to predict HbA1c, such that when adolescents had both low emotional processing and low self-control, HbA1c was poorest. Also, both high emotional processing and self-control buffered negative effects of low capacity in the other in relation to HbA1c. The interaction of emotional processing × self-control predicted HbA1c over diabetes-specific self-efficacy, negative affect, and adherence. Conclusions These findings suggest the importance of emotional processing and self-control for health outcomes in adolescents with diabetes. PMID:22523404
High-efficiency induction motor drives using type-2 fuzzy logic
NASA Astrophysics Data System (ADS)
Khemis, A.; Benlaloui, I.; Drid, S.; Chrifi-Alaoui, L.; Khamari, D.; Menacer, A.
2018-03-01
In this work we propose to develop an algorithm for improving the efficiency of an induction motor using type-2 fuzzy logic. Vector control is used to control this motor due to the high performances of this strategy. The type-2 fuzzy logic regulators are developed to obtain the optimal rotor flux for each torque load by minimizing the copper losses. We have compared the performances of our fuzzy type-2 algorithm with the type-1 fuzzy one proposed in the literature. The proposed algorithm is tested with success on the dSPACE DS1104 system even if there is parameters variance.
Amemori, Shogo; Kokado, Kenta; Sada, Kazuki
2012-05-23
The de novo design of thermosensitive polymers in solution has been achieved by using the addition of small organic molecules (or "effectors"). Hydrogen bonding as an attractive polymer-polymer or polymer-effector interaction substantially dominates the responsivity, causing facile switching between LCST-type and UCST-type phase transitions, control of the transition temperature, and further coincidence of the two transitions. Small molecules having a high affinity for the polymer induce UCST-type phase behavior, whereas those having a low affinity for the polymer showed LCST-type phase behavior.
Serum proteomics reveals systemic dysregulation of innate immunity in type 1 diabetes
Fillmore, Thomas L.; Schepmoes, Athena A.; Clauss, Therese R.W.; Gritsenko, Marina A.; Mueller, Patricia W.; Rewers, Marian; Atkinson, Mark A.; Smith, Richard D.
2013-01-01
Using global liquid chromatography-mass spectrometry (LC-MS)–based proteomics analyses, we identified 24 serum proteins that were significantly variant between those with type 1 diabetes (T1D) and healthy controls. Functionally, these proteins represent innate immune responses, the activation cascade of complement, inflammatory responses, and blood coagulation. Targeted verification analyses were performed on 52 surrogate peptides representing these proteins, with serum samples from an antibody standardization program cohort of 100 healthy control and 50 type 1 diabetic subjects. 16 peptides were verified as having very good discriminating power, with areas under the receiver operating characteristic curve ≥0.8. Further validation with blinded serum samples from an independent cohort (10 healthy control and 10 type 1 diabetics) demonstrated that peptides from platelet basic protein and C1 inhibitor achieved both 100% sensitivity and 100% specificity for classification of samples. The disease specificity of these proteins was assessed using sera from 50 age-matched type 2 diabetic individuals, and a subset of proteins, C1 inhibitor in particular, were exceptionally good discriminators between these two forms of diabetes. The panel of biomarkers distinguishing those with T1D from healthy controls and those with type 2 diabetes suggests that dysregulated innate immune responses may be associated with the development of this disorder. PMID:23277452
Self-Control, Daily Negative Affect and Blood Glucose Control in Adolescents with Type 1 Diabetes
Lansing, Amy Hughes; Berg, Cynthia A.; Butner, Jonathan; Wiebe, Deborah J.
2016-01-01
Objective For adolescents with type 1 diabetes, maintaining optimal daily blood glucose control is a complex self-regulatory process that likely requires self-control. This study examined whether higher self-control was associated with lower daily negative affect about diabetes and, in turn, better daily blood glucose control, i.e., lower mean daily blood glucose (MBG) and smaller standard deviations of daily blood glucose (SDBG), through two paths: 1) self-control maintaining lower mean level of negative affect and 2) self-control buffering the association of the number of daily diabetes problems with daily negative affect. Methods Adolescents (M age=12.87 years) with type 1 diabetes (n=180) completed an initial survey containing a self-report measure of self-control. Nightly electronic diaries were completed for 14 days where adolescents reported daily problems with and negative affect about diabetes, and used a study-provided blood glucose meter. Results Hypotheses were examined through multilevel modeling. Lower mean levels of daily negative affect partially mediated the relation between higher adolescent self-control and lower MBG. Adolescent self-control also buffered the association of the number of daily problems with daily negative affect, and smaller fluctuations in daily negative affect were associated with lower SDBG. Conclusions Adolescent self-control is associated with daily affect regulatory processes that may influence MBG. However, fluctuations in daily negative affect about diabetes may represent a unique within-person daily process associated with SDBG. These findings suggest that studies examining daily disease processes and interventions targeting daily affect regulation may be important to improving health in adolescents with type 1 diabetes. PMID:26914647
How-to-Do-It: Infection Control Guidelines for Blood Typing & Blood Smear Labs.
ERIC Educational Resources Information Center
Vetter, Edwin A.
1989-01-01
Provides a set of guidelines for infection control of the Acquired Immune Deficiency Syndrome and the serum hepatitis viruses during blood typing procedures. Emphasizes that disposal of blood contaminated materials should comply with local health department recommendations. (RT)
Xiao, Shan; Zeng, Xiaoyun; Quan, Li; Zhu, Jun
2015-01-01
To explore the correlation between FTO (fat mass and obesity associated) gene, which is associated with 3 single nucleotide polymorphisms (SNP) of fat mass and obesity, type 2 diabetes and body mass index (BMI) in the Uygur population in northwest China. A total of 849 Uygur patients with type 2 diabetes mellitus were selected from the hospitalized patients in the First Affiliated Hospital of Xinjiang Medical University, the First People's Hospital of Kashi and the hospitals in the Turpan areas. At the same time, 873 cases of healthy persons who conducted a medical checkup in the physical examination centre of the above hospitals were enrolled as controls. The present investigation used the case-control research method, and physical examination and biochemical index determination were carried out. The Sequenom MassARRAY technology was employed in the detection of 3 SNP loci of the FTO gene. The representative population of each SNP in the control group was analyzed by Hardy-Weinberg law. The differences of each clinical parameter in the two groups were analyzed by t-test analysis. The differences of genotype and allele of each SNP in the two groups were analyzed by χ(2) test. BMI, waistline (WL), systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting blood glucose (FBG), total cholesterol (TC), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in the type 2 diabetes group were higher than those in the control group, while the high density lipoprotein (HDL) and low density lipoprotein (LDL) were lower than those of the control group; 2. The allele frequency of A of rs8050136 and rs9939609 in the type 2 diabetes mellitus group was higher than that of the control group. The BMI of the whole population and type 2 diabetes group with genotype C/A+A/A of rs8050136 was higher than that in C/C group, and the BMI with genotype T/A+A/A of rs9939609 was higher than that in group T/T. Stratification was conducted on BMI according to the normal, overweight and obesity criteria. There were significant differences in the distribution of genotype frequency of rs9939609 in the type 2 diabetes group and the control group of the normal BMI group. Single nucleotide mutation of rs7195539 in FTO gene may be a protective factor against the Uygur type 2 diabetes. Single nucleotide mutations of rs8050136 and rs9939609 may be associated with the Uygur type 2 diabetes and obesity, with A as a potential risk allele. The gene polymorphism of rs8050136 may correlate with type 2 diabetes mellitus through the function of BMI, while the correlation between rs9939609 gene polymorphism and type 2 diabetes is not depending from BMI.
Wermeling, Paulien R; van den Donk, Maureen; Gorter, Kees J; Ardine de Wit, G; van der Graaf, Yolanda; Rutten, Guy Ehm
2010-05-11
Scientific evidence for the frequency of monitoring of type 2 diabetes patients is lacking. If three-monthly control in general practice could be reduced to six-monthly control in some patients, this would on the one hand reduce the use of medical services including involvement of practice nurses, and thus reduce costs, and on the other hand alleviate the burden of people with type 2 diabetes. The goal of this study is to make primary diabetes care as efficient as possible for patients and health care providers. Therefore, we want to determine whether six-monthly monitoring of well-controlled type 2 diabetes patients in primary care leads to equivalent cardiometabolic control compared to the generally recommended three-monthly monitoring. The study is a randomised controlled patient-preference equivalence trial. Participants are asked if they prefer three-monthly (usual care) or six-monthly diabetes monitoring. If they do not have a preference, they are randomised to a three-monthly or six-monthly monitoring group. Patients are eligible for the study if they are between 40 and 80 years old, diagnosed with type 2 diabetes more than one year ago, treated by a general practitioner, not on insulin treatment, and with HbA1c < or = 7.5%, systolic blood pressure < or = 145 mmHg and total cholesterol < or = 5.2 mmol/l. The intervention group (six-monthly monitoring) will receive the same treatment with the same treatment targets as the control group (three-monthly monitoring). The intervention period will last one and a half year. After the intervention, the three-monthly and six-monthly monitoring groups are compared on equivalence of cardiometabolic control. Secondary outcome measures are HbA1c, blood pressure, cholesterol level, Body Mass Index, smoking behaviour, physical activity, loss of work due to illness, health status, diabetes-specific distress, satisfaction with treatment and adherence to medications. We will use intention-to-treat analysis with repeated measures. For outcomes that have only baseline and final measurements, we will use ANCOVA. Depending on the results, a cost-minimisation analysis or an incremental cost-effectiveness analysis will be done. This study will provide valuable information on the most efficient control frequency of well-controlled type 2 diabetes patients in primary care.
Molnár, Sándor; López, Inmaculada; Gámez, Manuel; Garay, József
2016-03-01
The paper is aimed at a methodological development in biological pest control. The considered one pest two-agent system is modelled as a verticum-type system. Originally, linear verticum-type systems were introduced by one of the authors for modelling certain industrial systems. These systems are hierarchically composed of linear subsystems such that a part of the state variables of each subsystem affect the dynamics of the next subsystem. Recently, verticum-type system models have been applied to population ecology as well, which required the extension of the concept a verticum-type system to the nonlinear case. In the present paper the general concepts and technics of nonlinear verticum-type control systems are used to obtain biological control strategies in a two-agent system. For the illustration of this verticum-type control, these tools of mathematical systems theory are applied to a dynamic model of interactions between the egg and larvae populations of the sugarcane borer (Diatraea saccharalis) and its parasitoids: the egg parasitoid Trichogramma galloi and the larvae parasitoid Cotesia flavipes. In this application a key role is played by the concept of controllability, which means that it is possible to steer the system to an equilibrium in given time. In addition to a usual linearization, the basic idea is a decomposition of the control of the whole system into the control of the subsystems, making use of the verticum structure of the population system. The main aim of this study is to show several advantages of the verticum (or decomposition) approach over the classical control theoretical model (without decomposition). For example, in the case of verticum control the pest larval density decreases below the critical threshold value much quicker than without decomposition. Furthermore, it is also shown that the verticum approach may be better even in terms of cost effectiveness. The presented optimal control methodology also turned out to be an efficient tool for the "in silico" analysis of the cost-effectiveness of different biocontrol strategies, e.g. by answering the question how far it is cost-effective to speed up the reduction of the pest larvae density, or along which trajectory this reduction should be carried out. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Yu, Pingping; Xiao, Xiangcheng; Wang, Linyun; Wang, Lei
2013-04-01
To investigate the self-management behaviors of patients with type 2 diabetes mellitus (DM) in a community and to explore the relationship between self-management behaviors and the glycemic control. A total of 211 type 2 DM patients in a community were selected by stratified random sampling. Patients were grouped according to the scores of self-management behaviors. The fasting plasma glucose (FPG), 2 h postprandial plasma glucose (2hPG) and glycated hemoglobin (HbA1C) level were tested. The differences between groups and relationship between self-management behaviors and glycemic control were analyzed. Self-management behaviors of most patients were not effective, and 2hPG and HbA1C were affected by different levels of the self-management behaviors (P<0.05). The self-management behaviors were negatively related to FPG (r=-0.277, P=0.015), 2hPG (r=-0.453, P=0.001), and HbA1C (r=-0.435, P=0.001). Glycemic control of the patients whose course of disease was over 5 years was significantly different due to different self-management behaviors. FPG level of the patients was positively related to alimentary control. The 2hPG level of the patients was positively related to alimentary control, medication persistence, and blood glucose self-monitoring. The HbA1C level of the patients was positively related to alimentary control and medication persistence. The times the patients received DM education, the way to use insulin, and the disease course of the patients were important factors to affect self-management behaviors of type 2 DM in the community. Self-management behaviors of type 2 DM patients in the community are not effective. Satisfactory self-management behaviors, specially the control of 2hPG and HbA1C are beneficial to glycemic control. We can improve the self-management behaviors in type 2 DM patients by paying attention to the disease course, the treatment method, and the contents and effect of DM education.
Eisenberg, Miriam H.; Lipsky, Leah M.; Dempster, Katherine; Liu, Aiyi; Nansel, Tonja R.
2016-01-01
Purpose Among adolescents with type 1 diabetes, disordered eating behaviors (DEB) are more prevalent and have more serious health implications than in adolescents without diabetes, necessitating identification of modifiable correlates of DEB in this population. This study hypothesized that 1) autonomous motivation and 2) controlled motivation for healthy eating (i.e., eating healthfully because it’s important to oneself versus important to others respectively) are associated with DEB among adolescents with type 1 diabetes. The third hypothesis was that baseline healthy eating self-efficacy moderates these associations. Methods Adolescents with T1D (n = 90; 13–16 years) participating in a behavioral nutrition intervention efficacy trial reported DEB, controlled and autonomous motivation, and self-efficacy at baseline, 6, 12, and 18 months. Linear mixed models estimated associations of controlled and autonomous motivation with DEB, adjusting for treatment group, BMI, socio-economic status, age, and gender. Separate models investigated the interaction of self-efficacy with each motivation type. Results Controlled motivation was positively associated with DEB (B=2.18±.33, p<.001); the association was stronger for those with lower self-efficacy (B= 3.33±.55, p<.001) than those with higher self-efficacy (B=1.36±.36, p<.001). Autonomous motivation was not associated with DEB (B=−.70± .43, p=.11). Conclusions Findings identify controlled motivation for healthy eating as a novel correlate of DEB among adolescents with type 1 diabetes and show that self-efficacy can modify this association. Motivation and self-efficacy for healthy eating represent potential intervention targets to reduce DEB in adolescents with type 1 diabetes. PMID:27567063
Piovesan, Fabiana; Tres, Glaucia S.; Moreira, Leila B.; Andrades, Michael E.; Lisboa, Hugo K.
2017-01-01
Diacerein seems to improve metabolic control and reduce inflammatory marker levels in individuals with type 2 diabetes mellitus (Type 2 DM), but for participants with chronic kidney disease (CKD) its effect is unknown. This study aimed to evaluate the effect of diacerein vs. placebo on urinary albumin/creatinine ratio (ACR), glomerular filtration rate (GFR), and inflammatory cytokines in type 2 DM participants with CKD. Blood pressure (BP) and metabolic control were secondary outcomes. This randomized, placebo-controlled, parallel trial of adjuvant treatment of type 2 DM with diacerein enrolled seventy-two participants with CKD, aged 30–80 years, with glycated hemoglobin levels from 53–97 mmol/mol (7.0–11.0%), receiving angiotensin-converting enzyme inhibitors or angiotensin receptor blockers and antidiabetic agents. Participants randomized to diacerein or placebo were followed-up up to 90 days. Both groups had a marked reduction in ACR, but there was no effect on glomerular filtration rate. While the diacerein group had reduced TNF-α levels at the 75th percentile with a borderline significance (P = 0.05), there were no changes in the IL levels at the 75th percentile. Diacerein prevented the increase in blood glucose to the level observed in the placebo group (P = 0.04), improving metabolic control by 74%, reducing 24-hour diastolic BP, nighttime systolic and diastolic BP compared to the placebo group. In conclusion, among patients with type 2 DM and CKD, diacerein does not have an effect on ACR or GFR, but slows metabolic control deterioration and is associated with lower nighttime systolic and diastolic blood pressure. Trial registration: Brazilian Clinical Trials Registry (Registro Brasileiro de Ensaios Clinicos; ReBeC) U1111-1156-0255 PMID:29049415
Piovesan, Fabiana; Tres, Glaucia S; Moreira, Leila B; Andrades, Michael E; Lisboa, Hugo K; Fuchs, Sandra C
2017-01-01
Diacerein seems to improve metabolic control and reduce inflammatory marker levels in individuals with type 2 diabetes mellitus (Type 2 DM), but for participants with chronic kidney disease (CKD) its effect is unknown. This study aimed to evaluate the effect of diacerein vs. placebo on urinary albumin/creatinine ratio (ACR), glomerular filtration rate (GFR), and inflammatory cytokines in type 2 DM participants with CKD. Blood pressure (BP) and metabolic control were secondary outcomes. This randomized, placebo-controlled, parallel trial of adjuvant treatment of type 2 DM with diacerein enrolled seventy-two participants with CKD, aged 30-80 years, with glycated hemoglobin levels from 53-97 mmol/mol (7.0-11.0%), receiving angiotensin-converting enzyme inhibitors or angiotensin receptor blockers and antidiabetic agents. Participants randomized to diacerein or placebo were followed-up up to 90 days. Both groups had a marked reduction in ACR, but there was no effect on glomerular filtration rate. While the diacerein group had reduced TNF-α levels at the 75th percentile with a borderline significance (P = 0.05), there were no changes in the IL levels at the 75th percentile. Diacerein prevented the increase in blood glucose to the level observed in the placebo group (P = 0.04), improving metabolic control by 74%, reducing 24-hour diastolic BP, nighttime systolic and diastolic BP compared to the placebo group. In conclusion, among patients with type 2 DM and CKD, diacerein does not have an effect on ACR or GFR, but slows metabolic control deterioration and is associated with lower nighttime systolic and diastolic blood pressure. Brazilian Clinical Trials Registry (Registro Brasileiro de Ensaios Clinicos; ReBeC) U1111-1156-0255.
The antioxidant status of coenzyme Q10 and vitamin E in children with type 1 diabetes.
Alkholy, Usama M; Abdalmonem, Nermin; Zaki, Ahmed; Elkoumi, Mohamed A; Hashim, Mustafa I Abu; Basset, Maha A A; Salah, Hossam E
2018-02-07
The purpose of this study was to evaluate the antioxidant status of plasma vitamin E and plasma and intracellular coenzyme Q10 in children with type 1 diabetes. This case-control study was conducted on 72 children with type 1 diabetes and compared to 48 healthy children, who were age, sex, and ethnicity-matched. The diabetic children were divided according to their glycosylated hemoglobin (A1c %) into two groups: poor and good glycemic control groups. All children underwent full history taking, clinical examination, and laboratory measurement of complete blood count, A1c %, plasma cholesterol, triglycerides, and vitamin E levels and coenzyme Q10 levels in plasma, erythrocytes, and platelets. Children with poor glycemic control showed significantly higher plasma vitamin E, coenzyme Q10, triglycerides, low-density lipoproteins, waist circumference/height ratio, cholesterol levels, and lower high-density lipoproteins and platelet coenzyme Q10 redox status in comparison to those with good glycemic control and the control group (p<0.05). Plasma coenzyme Q10 showed a positive correlation with the duration of type 1 diabetes, triglycerides, cholesterol, vitamin E, and A1c %, and negative correlation with the age of the diabetic group (p<0.05). The platelet redox status showed a negative correlation with the A1c % levels (r=-0.31; p=0.022) and the duration of type 1 diabetes (r=-0.35, p=0.012). Patients with type 1 diabetes, especially poorly controlled, had elevation of plasma vitamin E and coenzyme Q10 levels and decreased platelet redox status of coenzyme Q10, which may be an indicator of increased oxidative stress. Copyright © 2018 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.
He, Xingwei; Liu, Xintian; Liu, Wanjun; Wang, Bei; Liu, Yujian; Li, Zhuxi; Wang, Tao; Tan, Rong; Gao, Bo; Zeng, Hesong
2015-01-01
It is well-recognized that diabetes represents a powerful independent risk factor for cardiovascular diseases. However, very few studies have investigated the relationship between diabetes and risk of aortic dissection (AD). The aim of this case-control study was to evaluate the association between diabetes and risk of AD in Chinese population. A hospital-based case-control study, consisting of 2160 AD patients and 4320 controls, was conducted in a Chinese population. Demographic, clinical characteristics and risk factors were collected. Diabetes rate of patients with overall AD, Stanford type A AD and type B AD group was compared with that of corresponding matched control groups. Logistic regression analysis was used to estimate the odds ratios (OR) and 95% confidence intervals (95% CI) for relationship between diabetes and AD risk. The prevalence of diabetes was lower in AD cases than that of control subjects, whether it is the overall AD, type A AD or type B AD group (4.7% vs. 10.0%, 2.9% vs. 8.8%, 5.9% vs. 10.9%, all P<0.001). Furthermore, in multivariate model, diabetes was found to be associated with lower AD risk, which not only applies to the overall AD (OR = 0.2, 95%CI: 0.15-0.26), but also type A AD (OR = 0.12, 95% CI: 0.07-0.20) and type B AD (OR = 0.25, 95%CI: 0.18-0.33). We observed the paradoxical inverse relationship between DM and risk of AD in the Chinese population. These results suggest diabetes may play a protective role in the development of AD. However, further studies are needed to enrich related evidence, especially with regard to underlying mechanisms for these trends.
Relationships between skin cancers and blood groups--link between non-melanomas and ABO/Rh factors.
Cihan, Yasemin Benderli; Baykan, Halit; Kavuncuoglu, Erhan; Mutlu, Hasan; Kucukoglu, Mehmet Burhan; Ozyurt, Kemal; Oguz, Arzu
2013-01-01
This investigation focused on possible relationships between skin cancers and ABO/Rh blood groups. Between January 2005 and December 2012, medical data of 255 patients with skin cancers who were admitted to Kayseri Training and Research Hospital, Radiation Oncology and Plastic Surgery Outpatient Clinics were retrospectively analyzed. Blood groups of these patients were recorded. The control group consisted of 25701 healthy volunteers who were admitted to Kayseri Training and Research Hospital, Blood Donation Center between January 2010 and December 2011. The distribution of the blood groups of the patients with skin cancers was compared to the distribution of ABO/Rh blood groups of healthy controls. The association of the histopathological subtypes of skin cancer with the blood groups was also investigated. Of the patients, 50.2% had A type, 26.3% had O type, 16.1% had B type, and 7.5% had AB blood group with a positive Rh (+) in 77.3%. Of the controls, 44.3% had A type, 31.5% had 0 type, 16.1% had B type, and 8.1% had AB blood group with a positive Rh (+) in 87.8%. There was a statistically significant difference in the distribution of blood groups and Rh factors (A Rh (-) and 0 Rh positive) between the patients and controls. A total of 36.8% and 20.4% of the patients with basal cell carcinoma (BCC) had A Rh (+) and B Rh (+), respectively, while 39.2% and 27.6% of the controls had A Rh (+) and B Rh (+), respectively. A significant relationship was observed between the patients with BCC and controls in terms of A Rh (-) (p=0.001). Our study results demonstrated that there is a significant relationship between non-melanoma skin cancer and ABO/Rh factors.
Distributed intelligence for supervisory control
NASA Technical Reports Server (NTRS)
Wolfe, W. J.; Raney, S. D.
1987-01-01
Supervisory control systems must deal with various types of intelligence distributed throughout the layers of control. Typical layers are real-time servo control, off-line planning and reasoning subsystems and finally, the human operator. Design methodologies must account for the fact that the majority of the intelligence will reside with the human operator. Hierarchical decompositions and feedback loops as conceptual building blocks that provide a common ground for man-machine interaction are discussed. Examples of types of parallelism and parallel implementation on several classes of computer architecture are also discussed.
Feasibility Analysis and Evaluation of an Adaptive Tracked Vehicle Suspension and Control System
1975-06-01
CONTROL SYSTEM FINAL REPORT JUNE 1975 Contract No. DAAE07-72-C-017 D D C •W 6 1976 B t> y Robert M. Salemka National Water Lift Company A...spring rate which is as soft as a hydropneumatic system. 3.3 Adaptive Control The adaptive control was achieved by switching the jounce damping relief...inherently included in this type of system. The solenoid valves are of the normally closed type so that with no electrical power , the system will
New type of measuring and intelligent instrument for curing tobacco
NASA Astrophysics Data System (ADS)
Yi, Chui-Jie; Huang, Xieqing; Chen, Tianning; Xia, Hong
1993-09-01
A new type of measuring intelligent instrument for cured tobacco is presented in this paper. Based on fuzzy linguistic control principles the instrument is used to controlling the temperature and humidity during cured tobacco taking 803 1 singlechip computer as a center controller. By using methods of fuzzy weighted factors the cross coupling in curing procedures is decoupled. Results that the instrument has producted indicate the fuzzy controller in the instrument has perfect performance for process of cured tobacco as shown in figure
Yates, Dustin T; Cadaret, Caitlin N; Beede, Kristin A; Riley, Hannah E; Macko, Antoni R; Anderson, Miranda J; Camacho, Leticia E; Limesand, Sean W
2016-06-01
Intrauterine growth restriction (IUGR) reduces muscle mass and insulin sensitivity in offspring. Insulin sensitivity varies among muscle fiber types, with Type I fibers being most sensitive. Differences in fiber-type ratios are associated with insulin resistance in adults, and thus we hypothesized that near-term IUGR sheep fetuses exhibit reduced size and proportions of Type I fibers. Placental insufficiency-induced IUGR fetuses were ∼54% smaller (P < 0.05) than controls and exhibited hypoxemia and hypoglycemia, which contributed to 6.9-fold greater (P < 0.05) plasma norepinephrine and ∼53% lower (P < 0.05) plasma insulin concentrations. IUGR semitendinosus muscles contained less (P < 0.05) myosin heavy chain-I protein (MyHC-I) and proportionally fewer (P < 0.05) Type I and Type I/IIa fibers than controls, but MyHC-II protein concentrations, Type II fibers, and Type IIx fibers were not different. IUGR biceps femoris muscles exhibited similar albeit less dramatic differences in fiber type proportions. Type I and IIa fibers are more responsive to adrenergic and insulin regulation than Type IIx and may be more profoundly impaired by the high catecholamines and low insulin in our IUGR fetuses, leading to their proportional reduction. In both muscles, fibers of each type were uniformly smaller (P < 0.05) in IUGR fetuses than controls, which indicates that fiber hypertrophy is not dependent on type but rather on other factors such as myoblast differentiation or protein synthesis. Together, our findings show that IUGR fetal muscles develop smaller fibers and have proportionally fewer Type I fibers, which is indicative of developmental adaptations that may help explain the link between IUGR and adulthood insulin resistance. Copyright © 2016 the American Physiological Society.
Pena, M J; Lambers Heerspink, H J; Hellemons, M E; Friedrich, T; Dallmann, G; Lajer, M; Bakker, S J L; Gansevoort, R T; Rossing, P; de Zeeuw, D; Roscioni, S S
2014-09-01
Early detection of individuals with Type 2 diabetes mellitus or hypertension at risk for micro- or macroalbuminuria may facilitate prevention and treatment of renal disease. We aimed to discover plasma and urine metabolites that predict the development of micro- or macroalbuminuria. Patients with Type 2 diabetes (n = 90) and hypertension (n = 150) were selected from the community-cohort 'Prevention of REnal and Vascular End-stage Disease' (PREVEND) and the Steno Diabetes Center for this case-control study. Cases transitioned in albuminuria stage (from normo- to microalbuminuria or micro- to macroalbuminuria). Controls, matched for age, gender, and baseline albuminuria stage, remained in normo- or microalbuminuria stage during follow-up. Median follow-up was 2.9 years. Metabolomics were performed on plasma and urine. The predictive performance of a metabolite for albuminuria transition was assessed by the integrated discrimination index. In patients with Type 2 diabetes with normoalbuminuria, no metabolites discriminated cases from controls. In patients with Type 2 diabetes with microalbuminuria, plasma histidine was lower (fold change = 0.87, P = 0.02) and butenoylcarnitine was higher (fold change = 1.17, P = 0.007) in cases vs. controls. In urine, hexose, glutamine and tyrosine were lower in cases vs. controls (fold change = 0.20, P < 0.001; 0.32, P < 0.001; 0.51, P = 0.006, respectively). Adding the metabolites to a model of baseline albuminuria and estimated glomerular filtration rate metabolites improved risk prediction for macroalbuminuria transition (plasma integrated discrimination index = 0.28, P < 0.001; urine integrated discrimination index = 0.43, P < 0.001). These metabolites did not differ between hypertensive cases and controls without Type 2 diabetes. Type 2 diabetes-specific plasma and urine metabolites were discovered that predict the development of macroalbuminuria beyond established renal risk markers. These results should be confirmed in a large, prospective cohort. © 2014 The Authors. Diabetic Medicine © 2014 Diabetes UK.
Pancreas volume and fat fraction in children with Type 1 diabetes.
Regnell, S E; Peterson, P; Trinh, L; Broberg, P; Leander, P; Lernmark, Å; Månsson, S; Elding Larsson, H
2016-10-01
People with Type 1 diabetes have smaller pancreases than healthy individuals. Several diseases causing pancreatic atrophy are associated with pancreatic steatosis, but pancreatic fat in Type 1 diabetes has not been measured. This cross-sectional study aimed to compare pancreas size and fat fraction in children with Type 1 diabetes and controls. The volume and fat fraction of the pancreases of 22 children with Type 1 diabetes and 29 controls were determined using magnetic resonance imaging. Pancreas volume was 27% smaller in children with diabetes (median 34.9 cm(3) ) than in controls (47.8 cm(3) ; P < 0.001). Pancreas volume correlated positively with age in controls (P = 0.033), but not in children with diabetes (P = 0.649). Pancreas volume did not correlate with diabetes duration, but it did correlate positively with units of insulin/kg body weight/day (P = 0.048). A linear model of pancreas volume as influenced by age, body surface area and insulin units/kg body weight/day found that insulin dosage correlated with pancreas volume after controlling for both age and body surface area (P = 0.009). Pancreatic fat fraction was not significantly different between the two groups (1.34% vs. 1.57%; P = 0.891). Our findings do not indicate that pancreatic atrophy in Type 1 diabetes is associated with an increased pancreatic fat fraction, unlike some other diseases featuring reduced pancreatic volume. We speculate that our results may support the hypotheses that much of pancreatic atrophy in Type 1 diabetes occurs before the clinical onset of the disease and that exogenous insulin administration decelerates pancreatic atrophy after diabetes onset. © 2016 Diabetes UK.
Mazis, N; Papachristou, D J; Zouboulis, P; Tyllianakis, M; Scopa, C D; Megas, P
2009-12-01
Previous studies examining the multifidus fiber characteristics among low back pain (LBP) patients have not considered the variable of physical activity. The present study sought to investigate the muscle fiber size and type distribution of the lumbar multifidus muscle among LBP patient groups with different physical activity levels and healthy controls. Sixty-four patients were assigned to one of three groups named according to the physical activity level, determined for each patient by the International Physical Activity Questionnaire. These were low (LPA), medium (MPA) and high (HPA) physical activity groups. A control group comprising of 17 healthy individuals was also recruited. Muscle biopsy samples were obtained from the multifidus muscle at the level L4-L5. contrast with the control group, LBP patient groups showed a significantly higher Type II fiber distribution as well as reduced diameter in both fiber types (P<0.05). The physical activity level did not have an effect on multifidus characteristics since no significant differences were observed in fiber type and diameter (P>0.05) among LPA, MPA and HPA patient groups. Various pathological conditions were detected which were more pronounced in LBP groups compared to the control (P<0.05). Males had a larger fiber diameter compared to females for both fiber types (P<0.05). The results showed that the level of physical activity did not affect muscle fiber size and type distribution among LBP patients groups. These findings suggest that not only inactivity but also high physical activity levels can have an adverse effect on the multifidus muscle fiber characteristics.
Cathelicidin (LL-37) level in the scalp hair of patients with tinea capitis.
Abdelaal, Nagwa H; Rashed, Laila A; Ibrahim, Sahar Y; Abd El Halim, Mona H; Ghoneim, Noha; Saleh, Noha A; Saleh, Marwah A
2017-10-01
Antimicrobial peptides (AMPs) are considered an important first line of defense against pathogens. Cathelicidin LL-37 was upregulated in response to fungal infection. In this work we aimed to evaluate cathelicidin LL-37 in the hair of tinea capitis and compare it to normal controls. Hair samples were collected from 30 children and 30 controls aged from 2 to10 years old, and the level of cathelicidin LL-37 in the hair was detected by quantitative real-time PCR. The 30 patients were further subdivided into three subgroups according to their clinical type. Ten patients were scaly type, 10 patients were black dots type, and 10 patients were kerion type. Cathelicidin level in patients ranged from 6.0 to 17.5 with mean ± SD (11.3 ± 2.3) and in control ranged from 1.02 to 6.2, with mean ± SD (2.8 ± 1.5). There was a significant difference between the patients and controls regarding the cathelicidin level; P value was 0. The mean cathelicidin level was lowest in the kerion type10.73 ± 2.6 and highest in the black dot type 12.05 ± 2.76. However, there was no significant difference between the cathelicidin level of the different clinical types of tinea capitis; P value was 0.58. In conclusion, the level of cathelicidin LL-37 in hair specimens of human tinea capitis was significantly higher than controls. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Ganella, Eleni P; Burnett, Alice; Cheong, Jeanie; Thompson, Deanne; Roberts, Gehan; Wood, Stephen; Lee, Katherine; Duff, Julianne; Anderson, Peter J; Pantelis, Christos; Doyle, Lex W; Bartholomeusz, Cali
2015-03-01
Extremely preterm (EP, <28 weeks) and/or extremely low birth weight (ELBW, <1000 g) infants are at high risk of aberrant neurodevelopment. Sulcogyral folding patterns of the orbitofrontal cortex (OFC) are determined during the third trimester, however little is known about OFC patterning in EP/ELBW cohorts, for whom this gestational period is disturbed. This study investigated whether the distribution of OFC pattern types and frequency of intermediate and/or posterior orbital sulci (IOS/POS) differed between EP/ELBW and control adolescents. This study also investigated whether OFC pattern type was associated with mental illness or executive function outcome in adolescence. Magnetic resonance images of 194 EP/ELBW and 147 full term (>37 completed weeks) and/or normal birth weight (> 2500 g) adolescents were acquired, from which the OFC pattern of each hemisphere was classified as Type I, II, or III. Compared with controls, more EP/ELBW adolescents possessed a Type II in the left hemisphere (P = 0.019). The EP/ELBW group had fewer IOS (P = 0.024) and more POS (P = 0.021) in the left hemisphere compared with controls. OFC pattern type was not associated with mental illness, however in terms of executive functioning, Type III in the left hemisphere was associated with better parent-reported metacognition scores overall (P = 0.008) and better self-reported behavioral regulation scores in the control group (P = 0.001) compared with Type I. We show, for the first time that EP/ELBW birth is associated with changes in orbitofrontal development, and that specific patterns of OFC folding are associated with executive function at age 18 years in both EP/ELBW and control subjects. © 2014 Wiley Periodicals, Inc.
Rosenstock, Julio; Banarer, Salomon; Fonseca, Vivian A.; Inzucchi, Silvio E.; Sun, William; Yao, Wenqing; Hollis, Gregory; Flores, Robert; Levy, Richard; Williams, William V.; Seckl, Jonathan R.; Huber, Reid
2010-01-01
OBJECTIVE 11-β-hydroxysteroid dehydrogenase type 1 (11βHSD1) converts inactive cortisone into active cortisol, thereby amplifying intracellular glucocorticoid action. The efficacy and safety of the 11βHSD1 inhibitor INCB13739 were assessed when added to ongoing metformin monotherapy in patients with type 2 diabetes exhibiting inadequate glycemic control (A1C 7–11%). RESEARCH DESIGN AND METHODS This double-blind placebo-controlled paralleled study randomized 302 patients with type 2 diabetes (mean A1C 8.3%) on metformin monotherapy (mean 1.5 g/day) to receive one of five INCB13739 doses or placebo once daily for 12 weeks. The primary end point was the change in A1C at study end. Other end points included changes in fasting glucose, lipids, weight, adverse events, and safety. RESULTS After 12 weeks, 200 mg of INCB13739 resulted in significant reductions in A1C (−0.6%), fasting plasma glucose (−24 mg/dl), and homeostasis model assessment–insulin resistance (HOMA-IR) (−24%) compared with placebo. Total cholesterol, LDL cholesterol, and triglycerides were all significantly decreased in hyperlipidemic patients. Body weight decreased relative to placebo after INCB13739 therapy. A reversible dose-dependent elevation in adrenocorticotrophic hormone, generally within the normal reference range, was observed. Basal cortisol homeostasis, testosterone in men, and free androgen index in women were unchanged by INCB13739. Adverse events were similar across all treatment groups. CONCLUSIONS INCB13739 added to ongoing metformin therapy was efficacious and well tolerated in patients with type 2 diabetes who had inadequate glycemic control with metformin alone. 11βHSD1 inhibition offers a new potential approach to control glucose and cardiovascular risk factors in type 2 diabetes. PMID:20413513
Tait, Robert J; McKetin, Rebecca; Kay-Lambkin, Frances; Bennett, Kylie; Tam, Ada; Bennett, Anthony; Geddes, Jenny; Garrick, Adam; Christensen, Helen; Griffiths, Kathleen M
2012-06-25
The prevalence of amphetamine-type stimulant use is greater than that of opioids and cocaine combined. Currently, there are no approved pharmacotherapy treatments for amphetamine-type stimulant problems, but some face-to-face psychotherapies are of demonstrated effectiveness. However, most treatment services focus on alcohol or opioid disorders, have limited reach and may not appeal to users of amphetamine-type stimulants. Internet interventions have proven to be effective for some substance use problems but none has specifically targeted users of amphetamine-type stimulants. The study will use a randomized controlled trial design to evaluate the effect of an internet intervention for amphetamine-type stimulant problems compared with a waitlist control group. The primary outcome will be assessed as amphetamine-type stimulant use (baseline, 3 and 6 months). Other outcomes measures will include 'readiness to change', quality of life, psychological distress (K-10 score), days out of role, poly-drug use, help-seeking intention and help-seeking behavior. The intervention consists of three modules requiring an estimated total completion time of 90 minutes. The content of the modules was adapted from face-to-face clinical techniques based on cognitive behavior therapy and motivation enhancement. The target sample is 160 men and women aged 18 and over who have used amphetamine-type stimulants in the last 3 months. To our knowledge this will be the first randomized controlled trial of an internet intervention specifically developed for users of amphetamine-type stimulants. If successful, the intervention will offer greater reach than conventional therapies and may engage clients who do not generally seek treatment from existing service providers. Australian and New Zealand Clinical Trials Registry (http://www.anzctr.org.au/) ACTRN12611000947909.
2012-01-01
Background The prevalence of amphetamine-type stimulant use is greater than that of opioids and cocaine combined. Currently, there are no approved pharmacotherapy treatments for amphetamine-type stimulant problems, but some face-to-face psychotherapies are of demonstrated effectiveness. However, most treatment services focus on alcohol or opioid disorders, have limited reach and may not appeal to users of amphetamine-type stimulants. Internet interventions have proven to be effective for some substance use problems but none has specifically targeted users of amphetamine-type stimulants. Design/method The study will use a randomized controlled trial design to evaluate the effect of an internet intervention for amphetamine-type stimulant problems compared with a waitlist control group. The primary outcome will be assessed as amphetamine-type stimulant use (baseline, 3 and 6 months). Other outcomes measures will include ‘readiness to change’, quality of life, psychological distress (K-10 score), days out of role, poly-drug use, help-seeking intention and help-seeking behavior. The intervention consists of three modules requiring an estimated total completion time of 90 minutes. The content of the modules was adapted from face-to-face clinical techniques based on cognitive behavior therapy and motivation enhancement. The target sample is 160 men and women aged 18 and over who have used amphetamine-type stimulants in the last 3 months. Discussion To our knowledge this will be the first randomized controlled trial of an internet intervention specifically developed for users of amphetamine-type stimulants. If successful, the intervention will offer greater reach than conventional therapies and may engage clients who do not generally seek treatment from existing service providers. Trial registration Australian and New Zealand Clinical Trials Registry (www.anzctr.org.au/) ACTRN12611000947909 PMID:22731926
Szeto, Grace P Y; Straker, Leon M; O'Sullivan, Peter B
2009-01-01
Do symptomatic female office workers perform computing tasks with higher cervical postural muscle loads (in terms of higher amplitudes and less muscular rest) and more discomfort compared with asymptomatic individuals? Are these differences in postural muscle loads consistent across bilateral (typing) and unilateral (mousing) conditions? an experimental case-control study. 18 symptomatic female office workers and 21 asymptomatic female office workers. Three conditions (typing, mousing, and type-and-mouse) were performed in random order. Muscle load was measured as median amplitude and gap frequency using surface EMG of bilateral cervical erector spinae and upper trapezius. Discomfort was measured using a numerical rating scale. The case group demonstrated 4.3% (95% CI 0.1 to 8.4) higher amplitude during typing and 3.5% (95% CI 0.1 to 6.9) higher amplitude during type-and-mouse in the right cervical erector spinae compared with the control group. There was a similar difference between groups in the left cervical erector spinae which also demonstrated a 1.2 gaps/min (95% CI -2.3 to 0.0) lower frequency during typing. The case group had significantly higher discomfort during all conditions compared with the control group. The case group demonstrated higher median amplitudes and lower gap frequencies than the control group during bilateral conditions (typing and type-and-mouse) compared with unilateral conditions (mousing) for both muscle groups. There was increased amplitude and decreased muscular rest in the cervical erector spinae of office workers performing typing and mousing tasks. These findings may represent a mechanism underlying computer-related musculoskeletal disorders.
Brady, Cassandra C; Vannest, Jennifer J; Dolan, Lawrence M; Kadis, Darren S; Lee, Gregory R; Holland, Scott K; Khoury, Jane C; Shah, Amy S
2017-06-01
Children with type 1 diabetes demonstrate worse cognitive performance compared with their peers. Little is known regarding the cognitive and behavioral performance in obese adolescents with type 2 diabetes. Cross sectional evaluation of 20 obese adolescents with type 2 diabetes and 20 healthy adolescents was performed in Cincinnati, Ohio. Cognitive tests that included measures of processing speed, working memory, verbal and semantic fluency and parent reports of executive function and problem behavior were compared. Academic achievement and the relationship between cognitive/behavioral scores and diabetes duration and diabetes control (hemoglobin A1c) were assessed in the type 2 diabetes group only. The type 2 diabetes group had mean duration of diabetes of 2.8 ± 2.2 yr and hemoglobin A1c of 7.9 ± 2.2%. Adolescents with type 2 diabetes scored lower than controls on tests of working and verbal memory and processing speed (all p < 0.05) and worse for Internalizing, Externalizing, and Total Problems behaviors on the Child Behavior Checklist (all p < 0.05). Adolescents with type 2 diabetes scored below the population mean in academic achievement, most notably calculation. Working memory and processing speed were negatively correlated with duration of diabetes (r = -0.50 and -0.47, respectively, p < 0.05). Obese youth with type 2 diabetes score poorly compared with controls on multiple assessments of cognitive function and adaptive behavior. Further work is needed to determine if these effects are driven by obesity, diabetes or other demographic and socioeconomic risk factors. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Critical Differences between the Type-A Prone and Type-A Personalitites.
ERIC Educational Resources Information Center
Cassel, Russell N.; Cassel, Susie L.
1984-01-01
Type-A Prone and Type-A personalities were assessed on the basis of the Cassel Type-A Personality Assessment Profile. Statistical data analysis indicated differences in positive lifestyle, blood pressure, and self-control and no differences in negative lifestyle, pulse rate, or peripheral temperature. Type-A Prone and Type-A norm profiles were…
Tong, Wen Ting; Vethakkan, Shireene Ratna; Ng, Chirk Jenn
2015-01-01
Objective To explore factors influencing poor glycaemic control in people with type 2 diabetes using insulin. Research design A qualitative method comprising in-depth individual interviews. A semistructured interview guide was used. The interviews were audiorecorded, transcribed verbatim and analysed using a thematic approach. Participants Seventeen people with type 2 diabetes using insulin with glycated haemoglobin (HbA1c) ≥9% for >1 year. Setting The Primary Care Clinic and Diabetes Clinic in the University of Malaya Medical Centre (UMMC), Malaysia. Results Data analysis uncovered four themes: lifestyle challenges in adhering to medical recommendations; psychosocial and emotional hurdles; treatment-related factors; lack of knowledge about and self-efficacy in diabetes self-care. Conclusions Factors that explain the poor glycaemic control in people with type 2 diabetes using insulin were identified. Healthcare providers could use these findings to address patients’ concerns during consultations and help to improve glycaemic control. PMID:25633285
SVM-based tree-type neural networks as a critic in adaptive critic designs for control.
Deb, Alok Kanti; Jayadeva; Gopal, Madan; Chandra, Suresh
2007-07-01
In this paper, we use the approach of adaptive critic design (ACD) for control, specifically, the action-dependent heuristic dynamic programming (ADHDP) method. A least squares support vector machine (SVM) regressor has been used for generating the control actions, while an SVM-based tree-type neural network (NN) is used as the critic. After a failure occurs, the critic and action are retrained in tandem using the failure data. Failure data is binary classification data, where the number of failure states are very few as compared to the number of no-failure states. The difficulty of conventional multilayer feedforward NNs in learning this type of classification data has been overcome by using the SVM-based tree-type NN, which due to its feature to add neurons to learn misclassified data, has the capability to learn any binary classification data without a priori choice of the number of neurons or the structure of the network. The capability of the trained controller to handle unforeseen situations is demonstrated.
Wing, R R; Epstein, L H; Nowalk, M P; Scott, N; Koeske, R; Hagg, S
1986-11-01
Self-monitoring of blood glucose levels is currently being recommended for obese patients with type II diabetes to improve weight loss and glycemic control. To determine whether self-monitoring of blood glucose levels improves dietary compliance in these patients, 50 obese patients with type II diabetes were randomly assigned either to a standard behavioral weight control program or to a weight control program that included self-monitoring of blood glucose levels and focused on the weight-blood glucose relationship. Both groups lost significant amounts of weight and maintained their losses for at least one year; reductions in medication could be made for 70 percent of patients. These data suggest that the behavioral weight control used in this study may be of benefit to patients with type II diabetes. However, there was no evidence that the addition of self-monitoring of blood glucose levels to the treatment program improved the outcome in terms of weight loss, reduction in medication, dietary compliance, or mood state.
Banerji, Mary Ann; Dunn, Jeffrey D.
2013-01-01
Background The incidence and prevalence of type 2 diabetes continue to grow in the United States and worldwide, along with the growing prevalence of obesity. Patients with type 2 diabetes are at greater risk for comorbid cardiovascular (CV) disease (CVD), which dramatically affects overall healthcare costs. Objectives To review the impact of glycemic control and medication adherence on morbidity, mortality, and healthcare costs of patients with type 2 diabetes, and to highlight the need for new drug therapies to improve outcomes in this patient population. Methods This comprehensive literature search was conducted for the period between 2000 and 2013, using MEDLINE, to identify published articles that report the associations between glycemic control, medication adherence, CV morbidity and mortality, and healthcare utilization and costs. Search terms included “type 2 diabetes,” “adherence,” “compliance,” “nonadherence,” “drug therapy,” “resource use,” “cost,” and “cost-effectiveness.” Discussion Despite improvements in the management of CV risk factors in patients with type 2 diabetes, outcomes remain poor. The costs associated with the management of type 2 diabetes are increasing dramatically as the prevalence of the disease increases. Medication adherence to long-term drug therapy remains poor in patients with type 2 diabetes and contributes to poor glycemic control in this patient population, increased healthcare resource utilization and increased costs, as well as increased rates of comorbid CVD and mortality. Furthermore, poor adherence to established evidence-based guidelines for type 2 diabetes, including underdiagnosis and undertreatment, contributes to poor outcomes. New approaches to the treatment of patients with type 2 diabetes currently in development have the potential to improve medication adherence and consequently glycemic control, which in turn will help to reduce associated costs and healthcare utilization. Conclusions As the prevalence of type 2 diabetes and its associated comorbidities grows, healthcare costs will continue to increase, indicating a need for better approaches to achieve glycemic control and manage comorbid conditions. Drug therapies are needed that enhance patient adherence and persistence levels far above levels reported with currently available drugs. Improvements in adherence to treatment guidelines and greater rates of lifestyle modifications also are needed. A serious unmet need exists for greatly improved patient outcomes, more effective and more tolerable drugs, as well as marked improvements in adherence to treatment guidelines and drug therapy to positively impact healthcare costs and resource use. PMID:24991370
Gudjinu, Horlali Yao; Sarfo, Bismark
2017-07-26
The prevalence of type 2 diabetes mellitus in developing countries like Ghana continues to rise. This study seeks to assess the risk factors of type 2 diabetes mellitus in a Ghanaian setting. An unmatched case-control study among patients receiving care at the out-patient departments of the two major hospitals in the Ho Municipality. Patients diagnosed with type 2 diabetes mellitus were recruited. Appropriate controls with similar ages who were also patients receiving care at the out-patient department of these hospitals were recruited. Both cases and controls were administered a questionnaire that comprises of standardized and validated tools. These tools include WHO STEPs instrument, general practice physical activity questionnaire and rapid eating and activity assessment for patients. Additionally, the research participants were made to undergo physical examinations for weight, height, waist circumference and laboratory testing of fasting venous blood to assess the biochemical factors of interest namely fasting blood glucose and fasting lipids. Analysis of data was done using STATA version 11. A total of 136 (48 cases and 88 controls) participants of which 95 [39 (81.25%) cases and 56 (63.64%) controls] respondents underwent laboratory testing for fasting blood glucose and fasting blood lipid (total cholesterol, HDL cholesterol and triglycerides). Participants were aged between 35 and 62 years. This study reveals a number of risk factors for type 2 diabetes mellitus. Individuals in the middle socio-economic class have a greater risk of developing type 2 diabetes mellitus with an OR of 5.03 (p < 0.003; 95% CI 1.71-14.74). Eating large quantities/servings of fruits per seating provides protection against development of type 2 diabetes mellitus. A low physical activity level is a valid determinant of type 2 diabetes mellitus irrespective of body mass index, socio-economic level or place of residence. Individuals within the middle socio-economic level, who are physically inactive and do not consume large amounts of fruit are at greatest risk of developing type 2 diabetes mellitus. Living in a rural setting is attendant with high levels of physical activity this tends to protect rural residents from type 2 diabetes mellitus. Physical activity level confounds the relationship between place of residence and development of type 2 diabetes mellitus. Local policies should be realigned to attract individual of the middle socio-economic level to live in rural areas where they are more likely to be both physically active and consume more fruits thus averting the risks of developing T2DM.
Bidirectional active control of structures with type-2 fuzzy PD and PID
NASA Astrophysics Data System (ADS)
Paul, Satyam; Yu, Wen; Li, Xiaoou
2018-03-01
Proportional-derivative and proportional-integral-derivative (PD/PID) controllers are popular algorithms in structure vibration control. In order to maintain minimum regulation error, the PD/PID control require big proportional and derivative gains. The control performances are not satisfied because of the big uncertainties in the buildings. In this paper, type-2 fuzzy system is applied to compensate the unknown uncertainties, and is combined with the PD/PID control. We prove the stability of these fuzzy PD and PID controllers. The sufficient conditions can be used for choosing the gains of PD/PID. The theory results are verified by a two-storey building prototype. The experimental results validate our analysis.
NASA Astrophysics Data System (ADS)
Lei, Meizhen; Wang, Liqiang
2018-01-01
The halbach-type linear oscillatory motor (HT-LOM) is multi-variable, highly coupled, nonlinear and uncertain, and difficult to get a satisfied result by conventional PID control. An incremental adaptive fuzzy controller (IAFC) for stroke tracking was presented, which combined the merits of PID control, the fuzzy inference mechanism and the adaptive algorithm. The integral-operation is added to the conventional fuzzy control algorithm. The fuzzy scale factor can be online tuned according to the load force and stroke command. The simulation results indicate that the proposed control scheme can achieve satisfied stroke tracking performance and is robust with respect to parameter variations and external disturbance.
Evolutionary dynamics of enzymes.
Demetrius, L
1995-08-01
This paper codifies and rationalizes the large diversity in reaction rates and substrate specificity of enzymes in terms of a model which postulates that the kinetic properties of present-day enzymes are the consequence of the evolutionary force of mutation and selection acting on a class of primordial enzymes with poor catalytic activity and broad substrate specificity. Enzymes are classified in terms of their thermodynamic parameters, activation enthalpy delta H* and activation entropy delta S*, in their kinetically significant transition states as follows: type 1, delta H* > 0, delta S* < 0; type 2, delta H* < or = 0, delta S* < or = 0; type 3, delta H* > 0, delta S* > 0. We study the evolutionary dynamics of these three classes of enzymes subject to mutation, which acts at the level of the gene which codes for the enzyme and selection, which acts on the organism that contains the enzyme. Our model predicts the following evolutionary trends in the reaction rate and binding specificity for the three classes of molecules. In type 1 enzymes, evolution results in random, non-directional changes in the reaction rate and binding specificity. In type 2 and 3 enzymes, evolution results in a unidirectional increase in both the reaction rate and binding specificity. We exploit these results in order to codify the diversity in functional properties of present-day enzymes. Type 1 molecules will be described by intermediate reaction rates and broad substrate specificity. Type 2 enzymes will be characterized by diffusion-controlled rates and absolute substrate specificity. The type 3 catalysts can be further subdivided in terms of their activation enthalpy into two classes: type 3a (delta H* small) and type 3b (delta H* large). We show that type 3a will be represented by the same functional properties that identify type 2, namely, diffusion-controlled rates and absolute substrate specificity, whereas type 3b will be characterized by non-diffusion-controlled rates and absolute substrate specificity. We infer from this depiction of the three classes of enzymes, a general relation between the two functional properties, reaction rate and substrate specificity, namely, enzymes with diffusion-controlled rates have absolute substrate specificity. By appealing to energetic considerations, we furthermore show that enzymes with diffusion-controlled rates (types 2 and 3a) form a small subset of the class of all enzymes. This codification of present-day enzymes derived from an evolutionary model, essentially relates the structural properties of enzymes, as described by their thermodynamic parameters, to their functional properties, as represented by the reaction rate and substrate specificity.
Relaxation in control systems of subdifferential type
NASA Astrophysics Data System (ADS)
Tolstonogov, A. A.
2006-02-01
In a separable Hilbert space we consider a control system with evolution operators that are subdifferentials of a proper convex lower semicontinuous function depending on time. The constraint on the control is given by a multivalued function with non-convex values that is lower semicontinuous with respect to the variable states. Along with the original system we consider the system in which the constraint on the control is the upper semicontinuous convex-valued regularization of the original constraint. We study relations between the solution sets of these systems. As an application we consider a control variational inequality. We give an example of a control system of parabolic type with an obstacle.
System comprising interchangeable electronic controllers and corresponding methods
NASA Technical Reports Server (NTRS)
Steele, Glen F. (Inventor); Salazar, George A. (Inventor)
2009-01-01
A system comprising an interchangeable electronic controller is provided with programming that allows the controller to adapt a behavior that is dependent upon the particular type of function performed by a system or subsystem component. The system reconfigures the controller when the controller is moved from one group of subsystem components to another. A plurality of application programs are provided by a server from which the application program for a particular electronic controller is selected. The selection is based on criteria such as a subsystem component group identifier that identifies the particular type of function associated with the system or subsystem group of components.
Decentralized adaptive control of interconnected nonlinear systems with unknown control directions.
Huang, Jiangshuai; Wang, Qing-Guo
2018-03-01
In this paper, we propose a decentralized adaptive control scheme for a class of interconnected strict-feedback nonlinear systems without a priori knowledge of subsystems' control directions. To address this problem, a novel Nussbaum-type function is proposed and a key theorem is drawn which involves quantifying the interconnections of multiple Nussbaum-type functions of the subsystems with different control directions in a single inequality. Global stability of the closed-loop system and asymptotic stabilization of subsystems' output are proved and a simulation example is given to illustrate the effectiveness of the proposed control scheme. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.
Stefansson, Gunnar; Rosenberg, Andrew A
2005-01-29
We consider combinations of three types of control measures for the management of fisheries when the input information for policy decisions is uncertain. The methods considered include effort controls, catch quotas and area closures. We simulated a hypothetical fishery loosely based on the Icelandic cod fishery, using a simple spatially explicit dynamic model. We compared the performance with respect to conserving the resource and economic return for each type of control measure alone and in combination. In general, combining more than one type of primary direct control on fishing provides a greater buffer to uncertainty than any single form of fishery control alone. Combining catch quota control with a large closed area is a most effective system for reducing the risk of stock collapse and maintaining both short and long-term economic performance. Effort controls can also be improved by adding closed areas to the management scheme. We recommend that multiple control methods be used wherever possible and that closed areas should be used to buffer uncertainty. To be effective, these closed areas must be large and exclude all principal gears to provide real protection from fishing mortality.
Stefansson, Gunnar; Rosenberg, Andrew A.
2005-01-01
We consider combinations of three types of control measures for the management of fisheries when the input information for policy decisions is uncertain. The methods considered include effort controls, catch quotas and area closures. We simulated a hypothetical fishery loosely based on the Icelandic cod fishery, using a simple spatially explicit dynamic model. We compared the performance with respect to conserving the resource and economic return for each type of control measure alone and in combination. In general, combining more than one type of primary direct control on fishing provides a greater buffer to uncertainty than any single form of fishery control alone. Combining catch quota control with a large closed area is a most effective system for reducing the risk of stock collapse and maintaining both short and long-term economic performance. Effort controls can also be improved by adding closed areas to the management scheme. We recommend that multiple control methods be used wherever possible and that closed areas should be used to buffer uncertainty. To be effective, these closed areas must be large and exclude all principal gears to provide real protection from fishing mortality. PMID:15713593
Han, Su-Ting; Zhou, Ye; Yang, Qing Dan; Zhou, Li; Huang, Long-Biao; Yan, Yan; Lee, Chun-Sing; Roy, Vellaisamy A L
2014-02-25
Tunable memory characteristics are used in multioperational mode circuits where memory cells with various functionalities are needed in one combined device. It is always a challenge to obtain control over threshold voltage for multimode operation. On this regard, we use a strategy of shifting the work function of reduced graphene oxide (rGO) in a controlled manner through doping gold chloride (AuCl3) and obtained a gradient increase of rGO work function. By inserting doped rGO as floating gate, a controlled threshold voltage (Vth) shift has been achieved in both p- and n-type low voltage flexible memory devices with large memory window (up to 4 times for p-type and 8 times for n-type memory devices) in comparison with pristine rGO floating gate memory devices. By proper energy band engineering, we demonstrated a flexible floating gate memory device with larger memory window and controlled threshold voltage shifts.
Cryogenic Control System Migration and Developments towards the UNICOS CERN Standard at INFN
NASA Astrophysics Data System (ADS)
Modanese, Paolo; Calore, Andrea; Contran, Tiziano; Friso, Alessandro; Pengo, Marco; Canella, Stefania; Burioli, Sergio; Gallese, Benedetto; Inglese, Vitaliano; Pezzetti, Marco; Pengo, Ruggero
The cryogenic control systems at Laboratori Nazionali di Legnaro (LNL) are undergoing an important and radical modernization, allowing all the plants controls and supervision systems to be renewed in a homogeneous way towards the CERN-UNICOS standard. Before the UNICOS migration project started there were as many as 7 different types of PLC and 7 different types of SCADA, each one requiring its own particular programming language. In these conditions, even a simple modification and/or integration on the program or on the supervision, required the intervention of a system integrator company, specialized in its specific control system. Furthermore it implied that the operators have to be trained to learn the different types of control systems. The CERN-UNICOS invented for LHC [1] has been chosen due to its reliability and planned to run and be maintained for decades on. The complete migration is part of an agreement between CERN and INFN.
Szalai, Eszter; Deák, Eszter; Módis, László; Németh, Gábor; Berta, András; Nagy, Annamária; Felszeghy, Eniko; Káposzta, Rita; Malik, Rayaz A; Csutak, Adrienne
2016-03-01
The aim of this study was to quantify epithelial, stromal, and endothelial cell density, and subbasal nerve morphology in young patients with type 1 diabetes mellitus with and without diabetic retinopathy. A total of 28 young patients (mean age, 22.86 ± 9.05 years) with type 1 diabetes, with (n = 18) and without (n = 10) retinopathy, and 17 age-matched healthy control subjects (mean age, 26.53 ± 2.43 years) underwent corneal confocal microscopy (CCM). We found significantly lower epithelial (P < 0.0001) and endothelial (P = 0.001) cell densities and higher keratocyte cell density (P = 0.024) in patients with type 1 diabetes compared to controls. Significantly lower corneal nerve fiber density (P = 0.004), nerve branch density (P = 0.004), total nerve branch density (P = 0.04), and nerve fiber length (P = 0.001), and greater nerve fiber width (P = 0.04) were observed in patients with type 1 diabetes compared to control subjects. Significantly lower epithelial (P < 0.001) and endothelial (P = 0.02) cell densities, nerve branch density (P = 0.02), and nerve fiber length (P = 0.04), and significantly higher keratocyte cell density (P = 0.02) were found in patients with type 1 diabetes without retinopathy compared to control subjects. Corneal confocal microscopy identifies corneal cellular and small nerve fiber pathology in young patients with type 1 diabetes without retinopathy, which increases in severity in those with retinopathy. Corneal confocal microscopy appears to have considerable use as an imaging biomarker for early subclinical pathology in young patients with type 1 diabetes mellitus.
Guo, Jia; Whittemore, Robin; Jeon, Sangchoon; Grey, Margaret; Zhou, Zhi-Guang; He, Guo-Ping; Luo, Zi-Qiang
2015-05-01
To describe the patterns of diabetes self-management, depressive symptoms, metabolic control and satisfaction with quality of life over time in a cohort of Chinese youth with type 1 diabetes and to determine the relationships between these variables over time. Nurses have an important role in facilitating optimal self-management and health outcomes in youth with type 1 diabetes. Only a few studies have focused on patterns of diabetes adaptation over time in youth with type 1 diabetes, especially in China. Understanding changes in diabetes self-management, depressive symptoms, metabolic control and satisfaction with quality of life can facilitate assessment and intervention. This is a multi-site longitudinal descriptive study. Data for this report were collected at baseline with 136 eligible Chinese youth and 86 of them were followed up for the second time, 6-12 months after baseline data collection. Instruments to measure diabetes self-management, depressive symptoms, metabolic control and satisfaction with quality of life were collected at two time points. The data were collected from July 2009-October 2010. Linear mixed model analysis was used to analyse the longitudinal data. Self-management decreased over time; however, depressive symptoms, metabolic control and satisfaction with quality of life did not change from baseline to 6-12 months in this sample of Chinese youth with type 1 diabetes. A decrease in diabetes self-management over time was associated with worse metabolic control, while an increase in depressive symptoms over time was associated with poorer quality of life satisfaction in this sample. Chinese youth faced difficulties with diabetes adaptation, especially with the deterioration of diabetes self-management. Improving self-management and decreasing depressive symptoms may enhance diabetes adaptation with respect to metabolic control and quality of life. The deterioration of diabetes self-management over time in youth with type 1 diabetes in China deserves nurses' careful surveillance. Clinical interventions appropriate to the Chinese culture and health care system are needed to improve self-management and depressive symptoms in Chinese youth with type 1 diabetes. © 2014 John Wiley & Sons Ltd.
[Effect analysis on the two total load control methods for poisonous heavy metals].
Fu, Guo-Wei
2012-12-01
Firstly it should be made clear that implementation of source total load control for the first type of pollutants is necessary for environmental pollution control legislation and economic structure regulation. This kind of surveillance method has been more practical to be implemented since the Manual of the Industry Discharge Coefficient of First National Pollution Sources Investigation was published. The source total load control and water environment total load control are independent of each other and none of them is redundant, on the other side they can be complementary to each other. In the present, some local planning managers are blurring and confusing the contents and styles of the two surveillance methods. They just use the water total load control to manage all the pollutants, and source total load control is discarded, which results in the loss of control for the first type of pollutants especially for the drinking water source surveillance. There is a big difference between the water quality standards and the water environmental background concentration values for the first type of pollutants in the Environmental quality standard for surface water (GB 3838-88), which means that there are problems such as "relaxing the pollutant discharge permit" and "risk induced by valence state change". Taking an enterprise with 10t electrolytic lead production capacity as an example, there is a big difference between the allowable lead discharged loads by the two total load surveillance methods. In summary, it will bring a lot of harmful effects if the water total load control is implemented for the two types of pollutants, so the source total load control and water environmental total load control should be implemented strictly at the same time.
de Groot, Femke M; Voogt-Bode, Annieke; Passchier, Jan; Berger, Marjolein Y; Koes, Bart W; Verhagen, Arianne P
2011-06-01
The purpose of this study is to describe the effects in the placebo and "no treatment" arms in trials with headache patients. This is a secondary analysis of randomized controlled trials from 8 systematic reviews and selected trials with a "no treatment" or placebo control group. The different types of "no treatment" and placebo interventions were assessed and classified into 6 subgroups. The analyses were carried out according to type of outcome variable. In total, 119 studies were included (7119 participants). The mean recovery rate in all control groups was 35.7%. Significantly more participants recovered in control groups of pharmacological studies than in nonpharmacological studies: 38.5% vs 15.0%, respectively. Adults were more likely to recover in nonpharmacological studies and children in pharmacological studies. The mean recovery rate in the control groups was 36%. The recovery rate varied substantially between type of intervention and patients. Copyright © 2011 National University of Health Sciences. Published by Mosby, Inc. All rights reserved.
ERIC Educational Resources Information Center
Merakou, K.; Knithaki, A.; Karageorgos, G.; Theodoridis, D.; Barbouni, A.
2015-01-01
This study aims to assess the impact of a brief patient group education intervention in people with type 2 diabetes mellitus. The sample, 193 people with type 2 diabetes mellitus who were patients at the diabetic clinic of a primary health care setting in Attica, was assigned to two groups, intervention (138 individuals) and control group (55…
Hope, Lena; Juul-Kristensen, Birgit; Løvaas, Helene; Løvvik, Camilla; Maeland, Silje
2017-10-17
To investigate the prevalence and severity of subjective health complaints and describe illness perception in a population of Joint Hypermobility Syndrome or Ehlers-Danlos Syndrome-Hypermobile Type. This study was a postal survey with a questionnaire battery on demographic data, subjective health complaints inventory, and illness perception. A total of 110 individuals diagnosed with Joint Hypermobility Syndrome or Ehlers-Danlos Syndrome-Hypermobile Type from two specialized hospitals in Norway were offered participation. Further, 140 gender- and age-matched healthy controls from statistics Norway representing the general population were sent the questionnaire for reference. Overall response rate was 30.4% (n = 76), with 44.5% (n = 49) in Joint Hypermobility Syndrome/Ehlers-Danlos Syndrome-Hypermobile Type and 19.3% (n = 27) in controls. Subjective health complaints were significantly higher in Joint Hypermobility Syndrome/Ehlers-Danlos Syndrome-Hypermobile Type - than in the controls (32.06 vs. 11.08; p < 0.001). Further the brief illness perception questionnaire indicated that the adults with Joint Hypermobility Syndrome/Ehlers-Danlos Syndrome-Hypermobile Type had low understanding of their illness and symptoms (understanding, mean: 3.93, SD 2.88), and reported to have moderate personal and treatment control over their illness. Adults with Joint Hypermobility Syndrome/Ehlers-Danlos Syndrome-Hypermobile Type reported higher frequency and severity of subjective health complaints than the matched controls from the general adult population in Norway. Furthermore, Joint Hypermobility Syndrome/Ehlers-Danlos Syndrome-Hypermobile Type reported low understanding of their illness and associated symptoms, and moderate belief that their illness can be kept under control through self-management or treatment. This may indicate one of the reasons why prognosis for these patients is poor. Implications for rehabilitation Awareness of the complexity of the subjective health complaints and inquiry into illness perception could contribute with valuable information about these patients' perceptions of their condition. Such information could in its turn be of value for clinicians as they work towards facilitating a more holistic treatment approach, for example patient education and cognitive behavioural therapy.
Association of lipocalin-2 level, glycemic status and obesity in type 2 diabetes mellitus.
Elkhidir, Areej E; Eltaher, Halima B; Mohamed, Abdelrahim O
2017-07-14
Management of type 2 diabetes mellitus aims to maintain a normal glycemic status, which if not, it may lead to acute and/or chronic diabetic complications. Earlier studies found Lipocalin-2 elevated in complications associated with type 2 diabetes mellitus such as ischemic heart disease. These lipocalin-2 changes had been linked to obesity and uncontrolled diabetes. So, it could be useful to understand the effect of glycemic control and obesity on lipocalin-2. This was a case control study. Fifty-seven patients with type 2 diabetes and 30 non-diabetic controls participated after getting a written consent. Weight (kg), height (m) and waist circumference (cm) were measured then the body mass index (kg/m 2 ) was determined. Blood samples were collected after an overnight fasting. HbA1c, lipid profile and serum creatinine were measured using enzymatic methods. Lipocalin-2 was measured using sandwich ELISA. Lipocalin-2 was found significantly higher in patients with type 2 diabetes (P = 0.001). However, it had no significant correlation with any of the studied variables. Females had elevated BMI compared to males in the patients group (P < 0.001). HbA1c, serum creatinine, LDL and total cholesterol were elevated in patients with diabetes (P < 0.02). HDL was lower in the patients (P = 0.002). Significant elevation in HbA1c was found in male patients (P = 0.028) compared to female patients. Patients were further classified into controlled, uncontrolled diabetics, obese and non-obese. There was a significant elevation in waist circumference in uncontrolled diabetics compared to controlled ones. Lipocalin-2 had no significant changes between controlled and uncontrolled diabetics nor non-obese and obese patients. Patients with type 2 diabetes mellitus have elevated level of serum lipocalin-2. There was no significant association found between lipocalin-2 and glycemic control nor obesity.
The prevalence and predictors of disordered eating in women with coeliac disease.
Satherley, Rose-Marie; Howard, Ruth; Higgs, Suzanne
2016-12-01
The need for dietary management in coeliac disease may lead to the development of disordered eating. This study examined the prevalence of disordered eating and factors predicting disordered eating in women with coeliac disease, compared with other dietary-controlled conditions. A cross-sectional, online survey assessing psychological well-being, disordered eating behaviours (Eating Attitudes Test 26 (EAT-26); Binge Eating Scale (BES)) was distributed using online forums, to those with coeliac disease (N = 157), inflammatory bowel disease (N = 116), type two diabetes (N = 88) and healthy controls (N = 142). Hierarchical regressions were conducted to explore and compare the predictors of EAT-26 and BES scores across all groups. Within the coeliac disease group, a cluster analysis was conducted to examine types of disordered eating. Higher EAT-26 scores were found in those with coeliac disease and inflammatory bowel disease compared with healthy controls and type two diabetes; participants with a chronic health condition had higher BES than healthy control participants. The factors associated with EAT-26 scores differed across the dietary-controlled health conditions, with dietary management being important for those with coeliac disease. Psychological distress was associated with binge-eating behaviour across all groups. Cluster analyses found two types of disordered eating in coeliac disease; a binge eating type and a restrictive type. Disordered eating attitudes and behaviours are more prevalent in participants with chronic health conditions relative to healthy controls. The presence of binge eating behaviours in coeliac disease may be related to non-coeliac disease specific factors such as the distress associated with dietary-controlled illness. EAT-26 scores in coeliac disease are associated with disease specific factors, unique to following the gluten-free diet. These factors are important for identifying and supporting those with coeliac disease and disordered eating. Copyright © 2016 Elsevier Ltd. All rights reserved.
Association of faecal elastase 1 with non-fasting triglycerides in type 2 diabetes.
Rathmann, Wolfgang; Haastert, Burkhard; Oscarsson, Jan; Berglind, Niklas; Lindkvist, Björn; Wareham, Nicholas J
2016-01-01
Intestinal absorption of esterified fatty acids depends on exocrine pancreatic function and influences plasma triglycerides levels. The aim was to investigate the association of reduced exocrine pancreatic function (low fecal elastase-1; FE1) with plasma triglycerides in type 2 diabetes and controls without diabetes. FE1 (μg/g stool) and non-fasting plasma triglyceride measurements were undertaken in 544 type 2 diabetes patients (age: 63 ± 8 years) randomly selected from diabetes registers in Cambridgeshire (UK), and 544 matched controls (age, sex, practice) without diabetes. Linear regression models were fitted using FE1 as dependent and log-triglycerides as independent variable adjusting for sex, age, body mass index, alcohol consumption, serum lipase, HbA1c, and smoking. FE1 concentrations were lower (mean ± SD: 337 ± 204 vs. 437 ± 216 μg/g, p < 0.05) and plasma triglycerides were higher (geometric mean */: standard deviation factor: 2.2*/:1.9 vs. 1.6*/:1.8 mmol/l, p < 0.05) in type 2 diabetes compared to controls, respectively. Within the category of type 2 diabetes and controls separately, a 10% increase in plasma triglycerides was associated with 4.5 μg/g higher FE1 concentrations (p < 0.01) after adjusting for confounders. In contrast, in diabetes patients and controls with pathological FE1 (<100 μg/g), low FE1 levels were associated with high plasma triglycerides (significant only in controls). Non-fasting triglycerides were positively related to FE1 in both type 2 diabetes and controls suggesting that impairment of exocrine pancreas function is influencing plasma triglycerides. Marked loss of exocrine pancreatic function had the opposite effect, resulting in higher levels of plasma triglycerides. Copyright © 2016 IAP and EPC. Published by Elsevier B.V. All rights reserved.
Role of different types of Ca2+ channels and a reticulum-like Ca2+ pump in neurotransmitter release.
Fossier, P; Baux, G; Tauc, L
1993-01-01
The factors controlling the Ca2+ concentration directly responsible for triggering acetylcholine (ACh) release were investigated at an identified neuro-neuronal synapse of the Aplysia buccal ganglion. The types of presynaptic voltage-gated Ca2+ channels associated with transmitter release were determined by using selective blockers such as nifedipine, omega-conotoxin and a partially purified extract from the venom of a funnel web spider (FTx). L-type, N-type and P-type Ca2+ channels are present in the presynaptic neuron. The influx of Ca2+ through both N- and P-types induces the release of ACh whereas Ca2+ flowing through L-type channels modulates the duration of the presynaptic action potential by controlling the Ca(2+)-dependent K+ current. tBuBHQ, a blocker of the reticulum Ca2+ pump, induces a potentiation of evoked release without modifying the presynaptic Ca2+ influx. This seems to indicate that a part of the Ca2+ entering the presynaptic terminal through N- and P-type Ca2+ channels is sequestered in a presynaptic reticulum-like Ca2+ buffer preventing these ions from contributing to ACh release. To exert its control, this Ca2+ buffer must be located close to both the presynaptic Ca2+ channels and the transmitter release mechanism.
An Efficient Interval Type-2 Fuzzy CMAC for Chaos Time-Series Prediction and Synchronization.
Lee, Ching-Hung; Chang, Feng-Yu; Lin, Chih-Min
2014-03-01
This paper aims to propose a more efficient control algorithm for chaos time-series prediction and synchronization. A novel type-2 fuzzy cerebellar model articulation controller (T2FCMAC) is proposed. In some special cases, this T2FCMAC can be reduced to an interval type-2 fuzzy neural network, a fuzzy neural network, and a fuzzy cerebellar model articulation controller (CMAC). So, this T2FCMAC is a more generalized network with better learning ability, thus, it is used for the chaos time-series prediction and synchronization. Moreover, this T2FCMAC realizes the un-normalized interval type-2 fuzzy logic system based on the structure of the CMAC. It can provide better capabilities for handling uncertainty and more design degree of freedom than traditional type-1 fuzzy CMAC. Unlike most of the interval type-2 fuzzy system, the type-reduction of T2FCMAC is bypassed due to the property of un-normalized interval type-2 fuzzy logic system. This causes T2FCMAC to have lower computational complexity and is more practical. For chaos time-series prediction and synchronization applications, the training architectures with corresponding convergence analyses and optimal learning rates based on Lyapunov stability approach are introduced. Finally, two illustrated examples are presented to demonstrate the performance of the proposed T2FCMAC.
Logan, Gordon D; Crump, Matthew J C
2009-10-01
Everyone knows that attention to the details disrupts skilled performance, but little empirical evidence documents this fact. We show that attention to the hands disrupts skilled typewriting. We had skilled typists type words preceded by cues that told them to type only the letters assigned to one hand or to type all of the letters. Cuing the hands disrupted performance markedly, slowing typing and increasing the error rate (Experiment 1); these deleterious effects were observed even when no keystrokes were actually inhibited (Experiment 3). However, cuing the same letters with colors was not disruptive (Experiment 2). We account for the disruption with a hierarchical control model, in which an inner loop controls the hands and an outer loop controls what is typed. Typing letters using only one hand requires the outer loop to monitor the inner loop's output; the outer loop slows inner-loop cycle time to increase the likelihood of inhibiting responses with the unwanted hand. This produces the disruption.